Downlink partial beam failure recovery

ABSTRACT

Systems, apparatuses, and methods are described for beam (or any other communication resource) failure recovery in wireless communications. A wireless device may determine if only a subset of serving beams have failed, and may perform beam failure recovery on other serving beams that have not failed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/615,269, titled “Downlink Partial Beam Failure Recovery” and filed onJan. 9, 2018; U.S. Provisional Application No. 62/615,277, titled “BeamSelection in Beam Failure Recovery Request Retransmission” and filed onJan. 9, 2018; as well as U.S. application Ser. No. 16/243,714, titled“Beam Selection in Beam Failure Recovery Request Retransmission” andfiled on Jan. 9, 2019. The disclosure of each of these applications ishereby incorporated by reference in its entirety.

BACKGROUND

In wireless communications, communication disruptions may occur.Interference that may cause an initial disruption, such asdisconnection, may also prevent a reconnection. It is desired to improvewireless communications, including to improve reconnections, withoutadversely increasing signaling overhead and/or decreasing spectralefficiency.

SUMMARY

The following summary presents a simplified summary of certain features.The summary is not an extensive overview and is not intended to identifykey or critical elements.

Systems, apparatuses, and methods are described for communicationsassociated with beam failure recovery. A wireless device may detect abeam failure (or any other wireless/communication resource failure). Thewireless device may determine if only a subset of serving beams havefailed. The wireless device may perform beam failure recovery on otherserving beams that have not failed. If a beam failure recovery requestis repeated, the wireless device may send the second request using a newbeam a threshold distance, in time and/or frequency, from a beam usedfor the prior request.

These and other features and advantages are described in greater detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Some features are shown by way of example, and not by limitation, in theaccompanying drawings. In the drawings, like numerals reference similarelements.

FIG. 1 shows example sets of orthogonal frequency division multiplexing(OFDM) subcarriers.

FIG. 2 shows example transmission time and reception time for twocarriers in a carrier group.

FIG. 3 shows example OFDM radio resources.

FIG. 4 shows hardware elements of a base station and a wireless device.

FIG. 5A, FIG. 5B, FIG. 5C and FIG. 5D show examples for uplink anddownlink signal transmission.

FIG. 6 shows an example protocol structure with multi-connectivity.

FIG. 7 shows an example protocol structure with carrier aggregation (CA)and dual connectivity (DC).

FIG. 8 shows example timing advance group (TAG) configurations.

FIG. 9 shows example message flow in a random access process in asecondary TAG.

FIG. 10A and FIG. 10B show examples for interfaces between a 5G corenetwork and base stations.

FIG. 11A, FIG. 11B, FIG. 11C, FIG. 11D, FIG. 11E, and FIG. 11F showexamples for architectures of tight interworking between a 5G RAN and along term evolution (LTE) radio access network (RAN).

FIG. 12A, FIG. 12B, and FIG. 12C show examples for radio protocolstructures of tight interworking bearers.

FIG. 13A and FIG. 13B show examples for gNodeB (gNB) deployment.

FIG. 14 shows functional split option examples of a centralized gNBdeployment.

FIG. 15 shows an example diagram of a configuration of a synchronizationsignal (SS) Burst Set.

FIG. 16 shows example diagrams of Random Access (RA) procedures.

FIG. 17 shows an example diagram of a media access control (MAC) packetdata unit (PDU) comprising a MAC header and MAC random access responses(RARs).

FIG. 18A, FIG. 18B, and FIG. 18C show example diagrams of a MAC RARformat of an example MAC RAR comprising a timing advance command, uplink(UL) grant, and temporary cell-radio network temporary identifier for afour-step RA procedure.

FIG. 19 shows an example diagram of random access procedure in amultiple-beam system.

FIG. 20 shows an example diagram of a channel stateinformation-reference signal (CSI-RS) transmission in a multi-beamsystem.

FIG. 21 shows an example diagram of activation/Deactivation of a CSI-RSresources MAC Control Element and a CSI-RS command.

FIG. 22 shows an example diagram of a CSI request file for PDCCH/EPDCCHwith uplink DCI format in UE specific search space.

FIG. 23 shows an example diagram of a CSI-RS mapping in time andfrequency domains.

FIG. 24 shows an example diagram of downlink beam management procedures.

FIG. 25A and FIG. 25B show example diagrams of activation/deactivationMAC control elements.

FIG. 26 shows an example diagram of a sCellDeactivationTimer startingand CSI reporting for an SCell.

FIG. 27 shows an example diagram of multiple Bandwidth Parts (BWPs)configuration in a frequency domain.

FIG. 28 shows an example diagram of BWP inactivity timer and asCellDeactivationTimer relation for an activated SCell.

FIG. 29 shows an example diagram of semi-persistent (SP) CSIconfiguration with a CSI activation MAC control element (CE) or DCI anda CSI deactivation MAC CE or DCI.

FIG. 30A shows an example of a beam failure event.

FIG. 30B shows an example of a beam failure event.

FIG. 31 shows an example of a downlink beam failure recovery procedure.

FIG. 32 shows an example of sending a beam failure recovery request.

FIG. 33 shows an example of a wireless device configured for beamfailure recovery.

FIG. 34 shows an example of full and partial beam failure recoveryrequest transmissions.

FIG. 35 shows an example of a partial beam failure recovery withoperational beams.

FIG. 36 shows an example of a partial beam failure recovery with anoperational beam.

FIG. 37 shows an example of a partial beam failure selection scheme.

FIG. 38 shows an example of a partial beam failure selection scheme.

FIG. 39 shows an example of a partial beam failure selection scheme.

FIG. 40 shows an example of a partial beam failure recovery with athreshold.

FIG. 41 shows an example of a partial beam failure recovery on failedbeams.

FIG. 42 shows an example of a partial beam failure recovery on failedbeams with a threshold.

FIG. 43 shows an example of partial beam failure recovery by a wirelessdevice.

FIG. 44 shows an example of partial beam failure recovery by a basestation.

FIG. 45 shows an example of a plurality of candidate beams in a crowdedenvironment.

FIG. 46 shows an example of a beam selection based on thresholds.

FIG. 47 shows an example of a beam selection based on thresholds.

FIG. 48 shows an example of a beam selection based on a time difference.

FIG. 49 shows an example of a beam selection based on a time difference.

FIG. 50 shows an example of a beam selection based on a time difference.

FIG. 51A shows an example of a beam selection.

FIG. 51B shows an example of a beam selection.

FIG. 52 shows an example of beam failure recovery by a wireless device.

FIG. 53 shows an example of beam failure recovery by a base station.

FIG. 54 shows example elements of a computing device that may be used toimplement any of the various devices described herein

DETAILED DESCRIPTION

The accompanying drawings, which form a part hereof, show examples ofthe disclosure. It is to be understood that the examples shown in thedrawings and/or discussed herein are non-exclusive and that there areother examples of how the disclosure may be practiced.

The features described herein may enable operation of carrieraggregation and may be used in the technical field of multicarriercommunication systems. Examples may relate connection failures inmulticarrier communication systems.

The following acronyms are used throughout the present disclosure,provided below for convenience although other acronyms may be introducedin the detailed description:

3GPP 3rd Generation Partnership Project

5G 5th generation wireless systems

5GC 5G Core Network

ACK Acknowledgement

AMF Access and Mobility Management Function

ASIC application-specific integrated circuit

BLER block error rate

BPSK binary phase shift keying

CA carrier aggregation

CC component carrier

CDMA code division multiple access

CP cyclic prefix

CPLD complex programmable logic devices

CSI channel state information

CSS common search space

CU central unit

DC dual connectivity

DCI downlink control information

DFTS-OFDM discrete Fourier transform spreading OFDM

DL downlink

DU distributed unit

eLTE enhanced LTE

eNB evolved Node B

EPC evolved packet core

E-UTRAN evolved-universal terrestrial radio access network

FDD frequency division multiplexing

FPGA field programmable gate arrays

Fs-C Fs-control plane

Fs-U Fs-user plane

gNB next generation node B

HARQ hybrid automatic repeat request

HDL hardware description languages

ID identifier

IE information element

LTE long term evolution

MAC media access control

MCG master cell group

MeNB master evolved node B

MIB master information block

MME mobility management entity

mMTC massive machine type communications

NACK Negative Acknowledgement

NAS non-access stratum

NG CP next generation control plane core

NGC next generation core

NG-C NG-control plane

NG-U NG-user plane

NR MAC new radio MAC

NR PDCP new radio PDCP

NR PHY new radio physical

NR RLC new radio RLC

NR RRC new radio RRC

NR new radio

NSSAI network slice selection assistance information

OFDM orthogonal frequency division multiplexing

PCC primary component carrier

PCell primary cell

PDCCH physical downlink control channel

PDCP packet data convergence protocol

PDU packet data unit

PHICH physical HARQ indicator channel

PHY physical

PLMN public land mobile network

PSCell primary secondary cell

pTAG primary timing advance group

PUCCH physical uplink control channel

PUSCH physical uplink shared channel

QAM quadrature amplitude modulation

QPSK quadrature phase shift keying

RA random access

RACH random access channel

RAN radio access network

RAP random access preamble

RAR random access response

RB resource blocks

RBG resource block groups

RLC radio link control

RRC radio resource control

RRM radio resource management

RS reference signal

RSRP reference signal received power

RV redundancy version

SCC secondary component carrier

SCell secondary cell

SCG secondary cell group

SC-OFDM single carrier-OFDM

SDU service data unit

SeNB secondary evolved node B

SFN system frame number

S-GW serving gateway

SIB system information block

SC-OFDM single carrier orthogonal frequency division multiplexing

SRB signaling radio bearer

sTAG(s) secondary timing advance group(s)

TA timing advance

TAG timing advance group

TAI tracking area identifier

TAT time alignment timer

TDD time division duplexing

TDMA time division multiple access

TTI transmission time interval

TB transport block

UE user equipment

UL uplink

UPGW user plane gateway

VHDL VHSIC hardware description language

Xn-C Xn-control plane

Xn-U Xn-user plane

Xx-C Xx-control plane

Xx-U Xx-user plane

Examples may be implemented using various physical layer modulation andtransmission mechanisms. Example transmission mechanisms may include,but are not limited to: CDMA, OFDM, TDMA, Wavelet technologies, and/orthe like. Hybrid transmission mechanisms such as TDMA/CDMA, andOFDM/CDMA may also be employed. Various modulation schemes may be usedfor signal transmission in the physical layer. Examples of modulationschemes include, but are not limited to: phase, amplitude, code, acombination of these, and/or the like. An example radio transmissionmethod may implement QAM using BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM,and/or the like. Physical radio transmission may be enhanced bydynamically or semi-dynamically changing the modulation and codingscheme depending on transmission requirements and radio conditions.

FIG. 1 shows example sets of OFDM subcarriers. As shown in this example,arrow(s) in the diagram may depict a subcarrier in a multicarrier OFDMsystem. The OFDM system may use technology such as OFDM technology,DFTS-OFDM, SC-OFDM technology, or the like. For example, arrow 101 showsa subcarrier transmitting information symbols. FIG. 1 is shown as anexample, and a typical multicarrier OFDM system may include moresubcarriers in a carrier. For example, the number of subcarriers in acarrier may be in the range of 10 to 10,000 subcarriers. FIG. 1 showstwo guard bands 106 and 107 in a transmission band. As shown in FIG. 1,guard band 106 is between subcarriers 103 and subcarriers 104. Theexample set of subcarriers A 102 includes subcarriers 103 andsubcarriers 104. FIG. 1 also shows an example set of subcarriers B 105.As shown, there is no guard band between any two subcarriers in theexample set of subcarriers B 105. Carriers in a multicarrier OFDMcommunication system may be contiguous carriers, non-contiguouscarriers, or a combination of both contiguous and non-contiguouscarriers.

FIG. 2 shows an example timing arrangement with transmission time andreception time for two carriers. A multicarrier OFDM communicationsystem may include one or more carriers, for example, ranging from 1 to10 carriers. Carrier A 204 and carrier B 205 may have the same ordifferent timing structures. Although FIG. 2 shows two synchronizedcarriers, carrier A 204 and carrier B 205 may or may not be synchronizedwith each other. Different radio frame structures may be supported forFDD and TDD duplex mechanisms. FIG. 2 shows an example FDD frame timing.Downlink and uplink transmissions may be organized into radio frames201. In this example, radio frame duration is 10 milliseconds (msec).Other frame durations, for example, in the range of 1 to 100 msec mayalso be supported. Each 10 msec radio frame 201 may be divided into tenequally sized subframes 202. Other subframe durations such as including0.5 msec, 1 msec, 2 msec, and 5 msec may also be supported. Subframe(s)may comprise two or more slots (e.g., slots 206 and 207). For theexample of FDD, 10 subframes may be available for downlink transmissionand 10 subframes may be available for uplink transmissions in each 10msec interval. Uplink and downlink transmissions may be separated in thefrequency domain. A slot may be 7 or 14 OFDM symbols for the samesubcarrier spacing of up to 60 kHz with normal CP. A slot may be 14 OFDMsymbols for the same subcarrier spacing higher than 60 kHz with normalCP. A slot may include all downlink, all uplink, or a downlink part andan uplink part, and/or alike. Slot aggregation may be supported, forexample, data transmission may be scheduled to span one or multipleslots. For example, a mini-slot may start at an OFDM symbol in asubframe. A mini-slot may have a duration of one or more OFDM symbols.Slot(s) may include a plurality of OFDM symbols 203. The number of OFDMsymbols 203 in a slot 206 may depend on the cyclic prefix length andsubcarrier spacing.

FIG. 3 shows an example of OFDM radio resources. The resource gridstructure in time 304 and frequency 305 is shown in FIG. 3. The quantityof downlink subcarriers or RBs may depend, at least in part, on thedownlink transmission bandwidth 306 configured in the cell. The smallestradio resource unit may be called a resource element (e.g., 301).Resource elements may be grouped into resource blocks (e.g., 302).Resource blocks may be grouped into larger radio resources calledResource Block Groups (RBG) (e.g., 303). The transmitted signal in slot206 may be described by one or several resource grids of a plurality ofsubcarriers and a plurality of OFDM symbols. Resource blocks may be usedto describe the mapping of certain physical channels to resourceelements. Other pre-defined groupings of physical resource elements maybe implemented in the system depending on the radio technology. Forexample, 24 subcarriers may be grouped as a radio block for a durationof 5 msec. A resource block may correspond to one slot in the timedomain and 180 kHz in the frequency domain (for 15 kHz subcarrierbandwidth and 12 subcarriers).

Multiple numerologies may be supported. A numerology may be derived byscaling a basic subcarrier spacing by an integer N. Scalable numerologymay allow at least from 15 kHz to 480 kHz subcarrier spacing. Thenumerology with 15 kHz and scaled numerology with different subcarrierspacing with the same CP overhead may align at a symbol boundary every 1msec in a NR carrier.

FIG. 4 shows hardware elements of a base station 401 and a wirelessdevice 406. A communication network 400 may include at least one basestation 401 and at least one wireless device 406. The base station 401may include at least one communication interface 402, one or moreprocessors 403, and at least one set of program code instructions 405stored in non-transitory memory 404 and executable by the one or moreprocessors 403. The wireless device 406 may include at least onecommunication interface 407, one or more processors 408, and at leastone set of program code instructions 410 stored in non-transitory memory409 and executable by the one or more processors 408. A communicationinterface 402 in the base station 401 may be configured to engage incommunication with a communication interface 407 in the wireless device406, such as via a communication path that includes at least onewireless link 411. The wireless link 411 may be a bi-directional link.The communication interface 407 in the wireless device 406 may also beconfigured to engage in communication with the communication interface402 in the base station 401. The base station 401 and the wirelessdevice 406 may be configured to send and receive data over the wirelesslink 411 using multiple frequency carriers. Base stations, wirelessdevices, and other communication devices may include structure andoperations of transceiver(s). Transceivers, which may comprise both atransmitter and receiver, may be employed in devices such as wirelessdevices, base stations, relay nodes, and/or the like. Examples for radiotechnology implemented in the communication interfaces 402, 407 and thewireless link 411 are shown in FIG. 1, FIG. 2, FIG. 3, FIG. 5, andassociated text. The communication network 400 may comprise any numberand/or type of devices, such as, for example, computing devices,wireless devices, mobile devices, handsets, tablets, laptops, internetof things (IoT) devices, hotspots, cellular repeaters, computingdevices, and/or, more generally, user equipment (e.g., UE). Although oneor more of the above types of devices may be referenced herein (e.g.,UE, wireless device, computing device, etc.), it should be understoodthat any device herein may comprise any one or more of the above typesof devices or similar devices. The communication network 400, and anyother network referenced herein, may comprise an LTE network, a 5Gnetwork, or any other network for wireless communications. Apparatuses,systems, and/or methods described herein may generally be described asimplemented on one or more devices (e.g., wireless device, base station,eNB, gNB, computing device, etc.), in one or more networks, but it willbe understood that one or more features and steps may be implemented onany device and/or in any network. As used throughout, the term “basestation” may comprise one or more of: a base station, a node, a Node B,a gNB, an eNB, an ng-eNB, a relay node (e.g., an integrated access andbackhaul (IAB) node), a donor node (e.g., a donor eNB, a donor gNB,etc.), an access point (e.g., a WiFi access point), a computing device,a device capable of wirelessly communicating, or any other devicecapable of sending and/or receiving signals. As used throughout, theterm “wireless device” may comprise one or more of: a UE, a handset, amobile device, a computing device, a node, a device capable ofwirelessly communicating, or any other device capable of sending and/orreceiving signals. Any reference to one or more of these terms/devicesalso considers use of any other term/device mentioned above.

The communications network 400 may comprise Radio Access Network (RAN)architecture. The RAN architecture may comprise one or more RAN nodesthat may be a next generation Node B (gNB) (e.g., 401) providing NewRadio (NR) user plane and control plane protocol terminations towards afirst wireless device (e.g. 406). A RAN node may be a next generationevolved Node B (ng-eNB), providing Evolved UMTS Terrestrial Radio Access(E-UTRA) user plane and control plane protocol terminations towards asecond wireless device. The first wireless device may communicate with agNB over a Uu interface. The second wireless device may communicate witha ng-eNB over a Uu interface. Base station 401 may comprise one or moreof a gNB, ng-eNB, and/or the like.

A gNB or an ng-eNB may host functions such as: radio resource managementand scheduling, IP header compression, encryption and integrityprotection of data, selection of Access and Mobility Management Function(AMF) at User Equipment (UE) attachment, routing of user plane andcontrol plane data, connection setup and release, scheduling andtransmission of paging messages (originated from the AMF), schedulingand transmission of system broadcast information (originated from theAMF or Operation and Maintenance (O&M)), measurement and measurementreporting configuration, transport level packet marking in the uplink,session management, support of network slicing, Quality of Service (QoS)flow management and mapping to data radio bearers, support of wirelessdevices in RRC_INACTIVE state, distribution function for Non-AccessStratum (NAS) messages, RAN sharing, and dual connectivity or tightinterworking between NR and E-UTRA.

One or more gNBs and/or one or more ng-eNBs may be interconnected witheach other by means of Xn interface. A gNB or an ng-eNB may be connectedby means of NG interfaces to 5G Core Network (5GC). 5GC may comprise oneor more AMF/User Plane Function (UPF) functions. A gNB or an ng-eNB maybe connected to a UPF by means of an NG-User plane (NG-U) interface. TheNG-U interface may provide delivery (e.g., non-guaranteed delivery) ofuser plane Protocol Data Units (PDUs) between a RAN node and the UPF. AgNB or an ng-eNB may be connected to an AMF by means of an NG-Controlplane (e.g., NG-C) interface. The NG-C interface may provide functionssuch as NG interface management, UE context management, UE mobilitymanagement, transport of NAS messages, paging, PDU session management,configuration transfer or warning message transmission.

A UPF may host functions such as anchor point for intra-/inter-RadioAccess Technology (RAT) mobility (if applicable), external PDU sessionpoint of interconnect to data network, packet routing and forwarding,packet inspection and user plane part of policy rule enforcement,traffic usage reporting, uplink classifier to support routing trafficflows to a data network, branching point to support multi-homed PDUsession, QoS handling for user plane, for example, packet filtering,gating, Uplink (UL)/Downlink (DL) rate enforcement, uplink trafficverification (e.g. Service Data Flow (SDF) to QoS flow mapping),downlink packet buffering and/or downlink data notification triggering.

An AMF may host functions such as NAS signaling termination, NASsignaling security, Access Stratum (AS) security control, inter CoreNetwork (CN) node signaling for mobility between 3^(rd) GenerationPartnership Project (3GPP) access networks, idle mode UE reachability(e.g., control and execution of paging retransmission), registrationarea management, support of intra-system and inter-system mobility,access authentication, access authorization including check of roamingrights, mobility management control (subscription and policies), supportof network slicing and/or Session Management Function (SMF) selection

An interface may be a hardware interface, a firmware interface, asoftware interface, and/or a combination thereof. The hardware interfacemay include connectors, wires, electronic devices such as drivers,amplifiers, and/or the like. A software interface may include codestored in a memory device to implement protocol(s), protocol layers,communication drivers, device drivers, combinations thereof, and/or thelike. A firmware interface may include a combination of embeddedhardware and code stored in and/or in communication with a memory deviceto implement connections, electronic device operations, protocol(s),protocol layers, communication drivers, device drivers, hardwareoperations, combinations thereof, and/or the like.

The term configured may relate to the capacity of a device whether thedevice is in an operational or a non-operational state. Configured mayalso refer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ora non-operational state. The hardware, software, firmware, registers,memory values, and/or the like may be “configured” within a device,whether the device is in an operational or a nonoperational state, toprovide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics inthe device, whether the device is in an operational or a non-operationalstate.

A network (e.g., a 5G network) may include a multitude of base stations,providing a user plane NR PDCP/NR RLC/NR MAC/NR PHY and control plane(e.g., NR RRC) protocol terminations towards the wireless device. Thebase station(s) may be interconnected with other base station(s) (e.g.,employing an Xn interface). The base stations may also be connectedemploying, for example, an NG interface to an NGC. FIG. 10A and FIG. 10Bshow examples for interfaces between a 5G core network (e.g., NGC) andbase stations (e.g., gNB and eLTE eNB). For example, the base stationsmay be interconnected to the NGC control plane (e.g., NG CP) employingthe NG-C interface and to the NGC user plane (e.g., UPGW) employing theNG-U interface. The NG interface may support a many-to-many relationbetween 5G core networks and base stations.

A base station may include many sectors, for example: 1, 2, 3, 4, or 6sectors. A base station may include many cells, for example, rangingfrom 1 to 50 cells or more. A cell may be categorized, for example, as aprimary cell or secondary cell. At RRC connectionestablishment/re-establishment/handover, one serving cell may providethe NAS (non-access stratum) mobility information (e.g., TAI), and atRRC connection re-establishment/handover, one serving cell may providethe security input. This cell may be referred to as the Primary Cell(PCell). In the downlink, the carrier corresponding to the PCell may bethe Downlink Primary Component Carrier (DL PCC); in the uplink, thecarrier corresponding to the PCell may be the Uplink Primary ComponentCarrier (UL PCC). Depending on wireless device capabilities, SecondaryCells (SCells) may be configured to form together with the PCell a setof serving cells. In the downlink, the carrier corresponding to an SCellmay be a Downlink Secondary Component Carrier (DL SCC); in the uplink,the carrier corresponding to an SCell may be an Uplink SecondaryComponent Carrier (UL SCC). An SCell may or may not have an uplinkcarrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and a cell index. A carrier (downlinkor uplink) may belong to only one cell. The cell ID or cell index mayalso identify the downlink carrier or uplink carrier of the cell(depending on the context in which it is used). The cell ID may beequally referred to a carrier ID, and cell index may be referred tocarrier index. In implementation, the physical cell ID or cell index maybe assigned to a cell. A cell ID may be determined using asynchronization signal transmitted on a downlink carrier. A cell indexmay be determined using RRC messages. For example, reference to a firstphysical cell ID for a first downlink carrier may indicate that thefirst physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.Reference to a first carrier that is activated may equally mean that thecell comprising the first carrier is activated.

A device may be configured to operate as needed by freely combining anyof the example features described herein. The disclosed mechanisms maybe performed if certain criteria are met, for example, in a wirelessdevice, a base station, a radio environment, a network, a combination ofthe above, and/or the like. Example criteria may be based, at least inpart, on for example, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like. Ifthe one or more criteria are met, various example embodiments may besatisfied. Therefore, it may be possible to implement examples thatselectively implement disclosed protocols.

A base station may communicate with a variety of wireless devices.Wireless devices may support multiple technologies, and/or multiplereleases of the same technology. Wireless devices may have some specificcapability(ies) depending on its wireless device category and/orcapability(ies). A base station may comprise multiple sectors. Referenceto a base station communicating with a plurality of wireless devices mayindicate that a base station may communicate with a subset of the totalwireless devices in a coverage area. A plurality of wireless devices ofa given LTE or 5G release, with a given capability and in a given sectorof the base station, may be used. The plurality of wireless devices mayrefer to a selected plurality of wireless devices, and/or a subset oftotal wireless devices in a coverage area which perform according todisclosed methods, and/or the like. There may be a plurality of wirelessdevices in a coverage area that may not comply with the disclosedmethods, for example, because those wireless devices perform based onolder releases of LTE or 5G technology.

A base station may transmit (e.g., to a wireless device) one or moremessages (e.g. RRC messages) that may comprise a plurality ofconfiguration parameters for one or more cells. One or more cells maycomprise at least one primary cell and at least one secondary cell. AnRRC message may be broadcasted or unicasted to the wireless device.Configuration parameters may comprise common parameters and dedicatedparameters.

Services and/or functions of an RRC sublayer may comprise at least oneof: broadcast of system information related to AS and NAS; paginginitiated by 5GC and/or NG-RAN; establishment, maintenance, and/orrelease of an RRC connection between a wireless device and NG-RAN, whichmay comprise at least one of addition, modification and release ofcarrier aggregation; or addition, modification, and/or release of dualconnectivity in NR or between E-UTRA and NR. Services and/or functionsof an RRC sublayer may further comprise at least one of securityfunctions comprising key management; establishment, configuration,maintenance, and/or release of Signaling Radio Bearers (SRBs) and/orData Radio Bearers (DRBs); mobility functions which may comprise atleast one of a handover (e.g. intra NR mobility or inter-RAT mobility)and a context transfer; or a wireless device cell selection andreselection and control of cell selection and reselection. Servicesand/or functions of an RRC sublayer may further comprise at least one ofQoS management functions; a wireless device measurementconfiguration/reporting; detection of and/or recovery from radio linkfailure; or NAS message transfer to/from a core network entity (e.g.AMF, Mobility Management Entity (MME)) from/to the wireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive stateand/or an RRC_Connected state for a wireless device. In an RRC_Idlestate, a wireless device may perform at least one of: Public Land MobileNetwork (PLMN) selection; receiving broadcasted system information; cellselection/re-selection; monitoring/receiving a paging for mobileterminated data initiated by 5GC; paging for mobile terminated data areamanaged by 5GC; or DRX for CN paging configured via NAS. In anRRC_Inactive state, a wireless device may perform at least one of:receiving broadcasted system information; cell selection/re-selection;monitoring/receiving a RAN/CN paging initiated by NG-RAN/5GC; RAN-basednotification area (RNA) managed by NG-RAN; or DRX for RAN/CN pagingconfigured by NG-RAN/NAS. In an RRC_Idle state of a wireless device, abase station (e.g. NG-RAN) may keep a 5GC-NG-RAN connection (bothC/U-planes) for the wireless device; and/or store a UE AS context forthe wireless device. In an RRC_Connected state of a wireless device, abase station (e.g. NG-RAN) may perform at least one of: establishment of5GC-NG-RAN connection (both C/U-planes) for the wireless device; storinga UE AS context for the wireless device; transmit/receive of unicastdata to/from the wireless device; or network-controlled mobility basedon measurement results received from the wireless device. In anRRC_Connected state of a wireless device, an NG-RAN may know a cell thatthe wireless device belongs to.

System information (SI) may be divided into minimum SI and other SI. Theminimum SI may be periodically broadcast. The minimum SI may comprisebasic information required for initial access and information foracquiring any other SI broadcast periodically or provisioned on-demand,i.e. scheduling information. The other SI may either be broadcast, or beprovisioned in a dedicated manner, either triggered by a network or uponrequest from a wireless device. A minimum SI may be transmitted via twodifferent downlink channels using different messages (e.g.MasterInformationBlock and SystemInformationBlockType1). The other SImay be transmitted via SystemInformationBlockType2. For a wirelessdevice in an RRC_Connected state, dedicated RRC signaling may beemployed for the request and delivery of the other SI. For the wirelessdevice in the RRC_Idle state and/or the RRC_Inactive state, the requestmay trigger a random-access procedure.

A wireless device may send its radio access capability information whichmay be static. A base station may request what capabilities for awireless device to report based on band information. If allowed by anetwork, a temporary capability restriction request may be sent by thewireless device to signal the limited availability of some capabilities(e.g. due to hardware sharing, interference or overheating) to the basestation. The base station may confirm or reject the request. Thetemporary capability restriction may be transparent to 5GC (e.g., staticcapabilities may be stored in 5GC).

If CA is configured, a wireless device may have an RRC connection with anetwork. At RRC connection establishment/re-establishment/handoverprocedure, one serving cell may provide NAS mobility information, and atRRC connection re-establishment/handover, one serving cell may provide asecurity input. This cell may be referred to as the PCell. Depending onthe capabilities of the wireless device, SCells may be configured toform together with the PCell a set of serving cells. The configured setof serving cells for the wireless device may comprise one PCell and oneor more SCells.

The reconfiguration, addition and removal of SCells may be performed byRRC. At intra-NR handover, RRC may also add, remove, or reconfigureSCells for usage with the target PCell. If adding a new SCell, dedicatedRRC signaling may be employed to send all required system information ofthe SCell. In connected mode, wireless devices may not need to acquirebroadcasted system information directly from the SCells.

An RRC connection reconfiguration procedure may be used to modify an RRCconnection, (e.g. to establish, modify and/or release RBs, to performhandover, to setup, modify, and/or release measurements, to add, modify,and/or release SCells and cell groups). As part of the RRC connectionreconfiguration procedure, NAS dedicated information may be transferredfrom the network to the wireless device. TheRRCConnectionReconfiguration message may be a command to modify an RRCconnection. It may convey information for measurement configuration,mobility control, radio resource configuration (e.g. RBs, MAC mainconfiguration and physical channel configuration) comprising anyassociated dedicated NAS information and security configuration. If thereceived RRC Connection Reconfiguration message includes thesCellToReleaseList, the wireless device may perform an SCell release. Ifthe received RRC Connection Reconfiguration message includes thesCellToAddModList, the wireless device may perform SCell additions ormodification.

An RRC connection establishment (or reestablishment, resume) proceduremay be used to establish (or reestablish, resume) an RRC connection. AnRRC connection establishment procedure may comprise SRB1 establishment.The RRC connection establishment procedure may be used to transfer theinitial NAS dedicated information message from a wireless device toE-UTRAN. The RRCConnectionReestablishment message may be used tore-establish SRB1.

A measurement report procedure may be to transfer measurement resultsfrom a wireless device to NG-RAN. The wireless device may initiate ameasurement report procedure, for example, after successful securityactivation. A measurement report message may be employed to transmitmeasurement results.

FIG. 5A, FIG. 5B, FIG. 5C, and FIG. 5D show examples of architecture foruplink and downlink signal transmission. FIG. 5A shows an example for anuplink physical channel. The baseband signal representing the physicaluplink shared channel may perform the following processes, which may beperformed by the structures described below. These structures andcorresponding functions are shown as examples, and it is anticipatedthat other mechanisms may be implemented in various examples. Thestructures and corresponding functions may comprise, for example, one ormore scrambling devices 501A and 501B configured to perform scramblingof coded bits in each of the codewords to be transmitted on a physicalchannel; one or more modulation mappers 502A and 502B configured toperform modulation of scrambled bits to generate complex-valued symbols;a layer mapper 503 configured to perform mapping of the complex-valuedmodulation symbols onto one or several transmission layers; one or moretransform precoders 504A and 504B to generate complex-valued symbols; aprecoding device 505 configured to perform precoding of thecomplex-valued symbols; one or more resource element mappers 506A and506B configured to perform mapping of precoded complex-valued symbols toresource elements; one or more signal generators 507A and 507Bconfigured to perform the generation of a complex-valued time-domainDFTS-OFDM/SC-FDMA signal for each antenna port; and/or the like.

FIG. 5B shows an example for performing modulation and up-conversion tothe carrier frequency of the complex-valued DFTS-OFDM/SC-FDMA basebandsignal, for example, for each antenna port and/or for the complex-valuedphysical random access channel (PRACH) baseband signal. For example, thebaseband signal, represented as s₁(t), may be split, by a signalsplitter 510, into real and imaginary components, Re{s₁(t)} andIm{s₁(t)}, respectively. The real component may be modulated by amodulator 511A, and the imaginary component may be modulated by amodulator 511B. The output signal of the modulator 511A and the outputsignal of the modulator 511B may be mixed by a mixer 512. The outputsignal of the mixer 512 may be input to a filtering device 513, andfiltering may be employed by the filtering device 513 prior totransmission.

FIG. 5C shows an example structure for downlink transmissions. Thebaseband signal representing a downlink physical channel may perform thefollowing processes, which may be performed by structures describedbelow. These structures and corresponding functions are shown asexamples, and it is anticipated that other mechanisms may be implementedin various examples. The structures and corresponding functions maycomprise, for example, one or more scrambling devices 531A and 531Bconfigured to perform scrambling of coded bits in each of the codewordsto be transmitted on a physical channel; one or more modulation mappers532A and 532B configured to perform modulation of scrambled bits togenerate complex-valued modulation symbols; a layer mapper 533configured to perform mapping of the complex-valued modulation symbolsonto one or several transmission layers; a precoding device 534configured to perform precoding of the complex-valued modulation symbolson each layer for transmission on the antenna ports; one or moreresource element mappers 535A and 535B configured to perform mapping ofcomplex-valued modulation symbols for each antenna port to resourceelements; one or more OFDM signal generators 536A and 536B configured toperform the generation of complex-valued time-domain OFDM signal foreach antenna port; and/or the like.

FIG. 5D shows an example structure for modulation and up-conversion tothe carrier frequency of the complex-valued OFDM baseband signal foreach antenna port. For example, the baseband signal, represented as s₁^((p))(t), may be split, by a signal splitter 520, into real andimaginary components, Re{s₁ ^((p))(t)} and Im{s₁ ^((p))(t)},respectively. The real component may be modulated by a modulator 521A,and the imaginary component may be modulated by a modulator 521B. Theoutput signal of the modulator 521A and the output signal of themodulator 521B may be mixed by a mixer 522. The output signal of themixer 522 may be input to a filtering device 523, and filtering may beemployed by the filtering device 523 prior to transmission.

FIG. 6 and FIG. 7 show examples for protocol structures with CA andmulti-connectivity. NR may support multi-connectivity operation, wherebya multiple receiver/transmitter (RX/TX) wireless device in RRC_CONNECTEDmay be configured to utilize radio resources provided by multipleschedulers located in multiple gNBs connected via a non-ideal or idealbackhaul over the Xn interface. gNBs involved in multi-connectivity fora certain wireless device may assume two different roles: a gNB mayeither act as a master gNB (e.g., 600) or as a secondary gNB (e.g., 610or 620). In multi-connectivity, a wireless device may be connected toone master gNB (e.g., 600) and one or more secondary gNBs (e.g., 610and/or 620). Any one or more of the Master gNB 600 and/or the secondarygNBs 610 and 620 may be a Next Generation (NG) NodeB. The master gNB 600may comprise protocol layers NR MAC 601, NR RLC 602 and 603, and NR PDCP604 and 605. The secondary gNB may comprise protocol layers NR MAC 611,NR RLC 612 and 613, and NR PDCP 614. The secondary gNB may compriseprotocol layers NR MAC 621, NR RLC 622 and 623, and NR PDCP 624. Themaster gNB 600 may communicate via an interface 606 and/or via aninterface 607, the secondary gNB 610 may communicate via an interface615, and the secondary gNB 620 may communicate via an interface 625. Themaster gNB 600 may also communicate with the secondary gNB 610 and thesecondary gNB 621 via interfaces 608 and 609, respectively, which mayinclude Xn interfaces. For example, the master gNB 600 may communicatevia the interface 608, at layer NR PDCP 605, and with the secondary gNB610 at layer NR RLC 612. The master gNB 600 may communicate via theinterface 609, at layer NR PDCP 605, and with the secondary gNB 620 atlayer NR RLC 622.

FIG. 7 shows an example structure for the UE side MAC entities, forexample, if a Master Cell Group (MCG) and a Secondary Cell Group (SCG)are configured. Media Broadcast Multicast Service (MBMS) reception maybe included but is not shown in this figure for simplicity.

In multi-connectivity, the radio protocol architecture that a particularbearer uses may depend on how the bearer is set up. As an example, threealternatives may exist, an MCG bearer, an SCG bearer, and a splitbearer, such as shown in FIG. 6. NR RRC may be located in a master gNBand SRBs may be configured as a MCG bearer type and may use the radioresources of the master gNB. Multi-connectivity may have at least onebearer configured to use radio resources provided by the secondary gNB.Multi-connectivity may or may not be configured or implemented.

For multi-connectivity, the wireless device may be configured withmultiple NR MAC entities: e.g., one NR MAC entity for a master gNB, andother NR MAC entities for secondary gNBs. In multi-connectivity, theconfigured set of serving cells for a wireless device may comprise twosubsets: e.g., the Master Cell Group (MCG) including the serving cellsof the master gNB, and the Secondary Cell Groups (SCGs) including theserving cells of the secondary gNBs.

At least one cell in a SCG may have a configured UL component carrier(CC) and one of the UL CCs, for example, named PSCell (or PCell of SCG,or sometimes called PCell), may be configured with PUCCH resources. Ifthe SCG is configured, there may be at least one SCG bearer or one splitbearer. If a physical layer problem or a random access problem on aPSCell occurs or is detected, if the maximum number of NR RLCretransmissions has been reached associated with the SCG, or if anaccess problem on a PSCell during a SCG addition or a SCG change occursor is detected, then an RRC connection re-establishment procedure maynot be triggered, UL transmissions towards cells of the SCG may bestopped, a master gNB may be informed by the wireless device of a SCGfailure type, and for a split bearer the DL data transfer over themaster gNB may be maintained. The NR RLC Acknowledge Mode (AM) bearermay be configured for the split bearer. Like the PCell, a PSCell may notbe de-activated. The PSCell may be changed with an SCG change (e.g.,with a security key change and a RACH procedure). A direct bearer typemay change between a split bearer and an SCG bearer, or a simultaneousconfiguration of an SCG and a split bearer may or may not be supported.

A master gNB and secondary gNBs may interact for multi-connectivity. Themaster gNB may maintain the RRM measurement configuration of thewireless device, and the master gNB may, (e.g., based on receivedmeasurement reports, and/or based on traffic conditions and/or bearertypes), decide to ask a secondary gNB to provide additional resources(e.g., serving cells) for a wireless device. If a request from themaster gNB is received, a secondary gNB may create a container that mayresult in the configuration of additional serving cells for the wirelessdevice (or the secondary gNB decide that it has no resource available todo so). For wireless device capability coordination, the master gNB mayprovide some or all of the Active Set (AS) configuration and thewireless device capabilities to the secondary gNB. The master gNB andthe secondary gNB may exchange information about a wireless deviceconfiguration, such as by employing NR RRC containers (e.g., inter-nodemessages) carried in Xn messages. The secondary gNB may initiate areconfiguration of its existing serving cells (e.g., PUCCH towards thesecondary gNB). The secondary gNB may decide which cell is the PSCellwithin the SCG. The master gNB may or may not change the content of theNR RRC configuration provided by the secondary gNB. In an SCG additionand an SCG SCell addition, the master gNB may provide the latestmeasurement results for the SCG cell(s). Both a master gNB and asecondary gNBs may know the system frame number (SFN) and subframeoffset of each other by operations, administration, and maintenance(OAM) (e.g., for the purpose of discontinuous reception (DRX) alignmentand identification of a measurement gap). If adding a new SCG SCell,dedicated NR RRC signaling may be used for sending required systeminformation of the cell for CA, except, for example, for the SFNacquired from an MIB of the PSCell of an SCG.

FIG. 7 shows an example of dual-connectivity (DC) for two MAC entitiesat a wireless device side. A first MAC entity may comprise a lower layerof an MCG 700, an upper layer of an MCG 718, and one or moreintermediate layers of an MCG 719. The lower layer of the MCG 700 maycomprise, for example, a paging channel (PCH) 701, a broadcast channel(BCH) 702, a downlink shared channel (DL-SCH) 703, an uplink sharedchannel (UL-SCH) 704, and a random access channel (RACH) 705. The one ormore intermediate layers of the MCG 719 may comprise, for example, oneor more hybrid automatic repeat request (HARQ) processes 706, one ormore random access control processes 707, multiplexing and/orde-multiplexing processes 709, logical channel prioritization on theuplink processes 710, and a control processes 708 providing control forthe above processes in the one or more intermediate layers of the MCG719. The upper layer of the MCG 718 may comprise, for example, a pagingcontrol channel (PCCH) 711, a broadcast control channel (BCCH) 712, acommon control channel (CCCH) 713, a dedicated control channel (DCCH)714, a dedicated traffic channel (DTCH) 715, and a MAC control 716.

A second MAC entity may comprise a lower layer of an SCG 720, an upperlayer of an SCG 738, and one or more intermediate layers of an SCG 739.The lower layer of the SCG 720 may comprise, for example, a BCH 722, aDL-SCH 723, an UL-SCH 724, and a RACH 725. The one or more intermediatelayers of the SCG 739 may comprise, for example, one or more HARQprocesses 726, one or more random access control processes 727,multiplexing and/or de-multiplexing processes 729, logical channelprioritization on the uplink processes 730, and a control processes 728providing control for the above processes in the one or moreintermediate layers of the SCG 739. The upper layer of the SCG 738 maycomprise, for example, a BCCH 732, a DCCH 714, a DTCH 735, and a MACcontrol 736.

Serving cells may be grouped in a TA group (TAG). Serving cells in oneTAG may use the same timing reference. For a given TAG, a wirelessdevice may use at least one downlink carrier as a timing reference. Fora given TAG, a wireless device may synchronize uplink subframe and frametransmission timing of uplink carriers belonging to the same TAG.Serving cells having an uplink to which the same TA applies maycorrespond to serving cells hosted by the same receiver. A wirelessdevice supporting multiple TAs may support two or more TA groups. One TAgroup may include the PCell and may be called a primary TAG (pTAG). In amultiple TAG configuration, at least one TA group may not include thePCell and may be called a secondary TAG (sTAG). Carriers within the sameTA group may use the same TA value and/or the same timing reference. IfDC is configured, cells belonging to a cell group (e.g., MCG or SCG) maybe grouped into multiple TAGs including a pTAG and one or more sTAGs.

FIG. 8 shows example TAG configurations. In Example 1, a pTAG comprisesa PCell, and an sTAG comprises an SCell1. In Example 2, a pTAG comprisesa PCell and an SCell1, and an sTAG comprises an SCell2 and an SCell3. InExample 3, a pTAG comprises a PCell and an SCell1, and an sTAG1comprises an SCell2 and an SCell3, and an sTAG2 comprises a SCell4. Upto four TAGs may be supported in a cell group (MCG or SCG), and otherexample TAG configurations may also be provided. In various examples,structures and operations are described for use with a pTAG and an sTAG.Some of the examples may be used for configurations with multiple sTAGs.

An eNB may initiate an RA procedure, via a PDCCH order, for an activatedSCell. The PDCCH order may be sent on a scheduling cell of this SCell.If cross carrier scheduling is configured for a cell, the schedulingcell may be different than the cell that is employed for preambletransmission, and the PDCCH order may include an SCell index. At least anon-contention based RA procedure may be supported for SCell(s) assignedto sTAG(s).

FIG. 9 shows an example of random access processes, and a correspondingmessage flow, in a secondary TAG. A base station, such as an eNB, maytransmit an activation command 900 to a wireless device, such as a UE.The activation command 900 may be transmitted to activate an SCell. Thebase station may also transmit a PDDCH order 901 to the wireless device,which may be transmitted, for example, after the activation command 900.The wireless device may begin to perform a RACH process for the SCell,which may be initiated, for example, after receiving the PDDCH order901. A wireless device may transmit to the base station (e.g., as partof a RACH process) a preamble 902 (e.g., Msg1), such as a random accesspreamble (RAP). The preamble 902 may be transmitted after or in responseto the PDCCH order 901. The wireless device may transmit the preamble902 via an SCell belonging to an sTAG. Preamble transmission for SCellsmay be controlled by a network using PDCCH format 1A. The base stationmay send a random access response (RAR) 903 (e.g., Msg2 message) to thewireless device. The RAR 903 may be after or in response to the preamble902 transmission via the SCell. The RAR 903 may be addressed to a randomaccess radio network temporary identifier (RA-RNTI) in a PCell commonsearch space (CSS). If the wireless device receives the RAR 903, theRACH process may conclude. The RACH process may conclude, for example,after or in response to the wireless device receiving the RAR 903 fromthe base station. After the RACH process, the wireless device maytransmit an uplink transmission 904. The uplink transmission 904 maycomprise uplink packets transmitted via the same SCell used for thepreamble 902 transmission.

Timing alignment (e.g., initial timing alignment) for communicationsbetween the wireless device and the base station may be performedthrough a random access procedure, such as described above regardingFIG. 9. The random access procedure may involve a wireless device, suchas a UE, transmitting a random access preamble and a base station, suchas an eNB, responding with an initial TA command NTA (amount of timingadvance) within a random access response window. The start of the randomaccess preamble may be aligned with the start of a corresponding uplinksubframe at the wireless device assuming NTA=0. The eNB may estimate theuplink timing from the random access preamble transmitted by thewireless device. The TA command may be derived by the eNB based on theestimation of the difference between the desired UL timing and theactual UL timing. The wireless device may determine the initial uplinktransmission timing relative to the corresponding downlink of the sTAGon which the preamble is transmitted.

The mapping of a serving cell to a TAG may be configured by a servingeNB with RRC signaling. The mechanism for TAG configuration andreconfiguration may be based on RRC signaling. If an eNB performs anSCell addition configuration, the related TAG configuration may beconfigured for the SCell. An eNB may modify the TAG configuration of anSCell by removing (e.g., releasing) the SCell and adding (e.g.,configuring) a new SCell (with the same physical cell ID and frequency)with an updated TAG ID. The new SCell with the updated TAG ID mayinitially be inactive subsequent to being assigned the updated TAG ID.The eNB may activate the updated new SCell and start scheduling packetson the activated SCell. In some examples, it may not be possible tochange the TAG associated with an SCell, but rather, the SCell may needto be removed and a new SCell may need to be added with another TAG. Forexample, if there is a need to move an SCell from an sTAG to a pTAG, atleast one RRC message, such as at least one RRC reconfiguration message,may be sent to the wireless device. The at least one RRC message may besent to the wireless device to reconfigure TAG configurations, forexample, by releasing the SCell and configuring the SCell as a part ofthe pTAG. If, for example, an SCell is added or configured without a TAGindex, the SCell may be explicitly assigned to the pTAG. The PCell maynot change its TA group and may be a member of the pTAG.

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g., to establish, modify and/or releaseRBs, to perform handover, to setup, modify, and/or release measurements,to add, modify, and/or release SCells). If the received RRC ConnectionReconfiguration message includes the sCellToReleaseList, the wirelessdevice may perform an SCell release. If the received RRC ConnectionReconfiguration message includes the sCellToAddModList, the wirelessdevice may perform SCell additions or modification.

In LTE Release-10 and Release-11 CA, a PUCCH transmission is onlytransmitted on a PCell (e.g., a PSCell) to an eNB. In LTE-Release 12 andearlier, a wireless device may transmit PUCCH information on one cell(e.g., a PCell or a PSCell) to a given eNB. As the number of CA capablewireless devices increases, and as the number of aggregated carriersincreases, the number of PUCCHs and the PUCCH payload size may increase.Accommodating the PUCCH transmissions on the PCell may lead to a highPUCCH load on the PCell. A PUCCH on an SCell may be used to offload thePUCCH resource from the PCell. More than one PUCCH may be configured.For example, a PUCCH on a PCell may be configured and another PUCCH onan SCell may be configured. One, two, or more cells may be configuredwith PUCCH resources for transmitting CSI, acknowledgment (ACK), and/ornon-acknowledgment (NACK) to a base station. Cells may be grouped intomultiple PUCCH groups, and one or more cells within a group may beconfigured with a PUCCH. One SCell may belong to one PUCCH group. SCellswith a configured PUCCH transmitted to a base station may be called aPUCCH SCell, and a cell group with a common PUCCH resource transmittedto the same base station may be called a PUCCH group.

A MAC entity may have a configurable timer, for example,timeAlignmentTimer, per TAG. The timeAlignmentTimer may be used tocontrol how long the MAC entity considers the serving cells belonging tothe associated TAG to be uplink time aligned. If a Timing AdvanceCommand MAC control element is received, the MAC entity may apply theTiming Advance Command for the indicated TAG; and/or the MAC entity maystart or restart the timeAlignmentTimer associated with a TAG that maybe indicated by the Timing Advance Command MAC control element. If aTiming Advance Command is received in a Random Access Response messagefor a serving cell belonging to a TAG, the MAC entity may apply theTiming Advance Command for this TAG and/or start or restart thetimeAlignmentTimer associated with this TAG. Additionally oralternatively, if the Random Access Preamble is not selected by the MACentity, the MAC entity may apply the Timing Advance Command for this TAGand/or start or restart the timeAlignmentTimer associated with this TAG.If the timeAlignmentTimer associated with this TAG is not running, theTiming Advance Command for this TAG may be applied, and thetimeAlignmentTimer associated with this TAG may be started. If thecontention resolution is not successful, a timeAlignmentTimer associatedwith this TAG may be stopped. If the contention resolution issuccessful, the MAC entity may ignore the received Timing AdvanceCommand. The MAC entity may determine whether the contention resolutionis successful or whether the contention resolution is not successful.

A timer may be considered to be running after it is started, until it isstopped, or until it expires; otherwise it may be considered to not berunning A timer can be started if it is not running or restarted if itis running. For example, a timer may be started or restarted from itsinitial value.

Features described herein may enable operation of multi-carriercommunications. Features may comprise a non-transitory tangible computerreadable media comprising instructions executable by one or moreprocessors to cause operation of multi-carrier communications. Thefeatures may comprise an article of manufacture that comprises anon-transitory tangible computer readable machine-accessible mediumhaving instructions encoded thereon for enabling programmable hardwareto cause a device (e.g. wireless communicator, UE, base station, etc.)to enable operation of multi-carrier communications. The devices hereinmay include processors, memory, interfaces, and/or the like. Featuresmay comprise communication networks comprising devices such as basestations, wireless devices (or user equipment: UE), servers, switches,antennas, and/or the like.

FIG. 10A and FIG. 10B show examples for interfaces between a 5G corenetwork (e.g., NGC) and base stations (e.g., gNB and eLTE eNB). A basestation, such as a gNB 1020, may be interconnected to an NGC 1010control plane employing an NG-C interface. The base station, forexample, the gNB 1020, may also be interconnected to an NGC 1010 userplane (e.g., UPGW) employing an NG-U interface. As another example, abase station, such as an eLTE eNB 1040, may be interconnected to an NGC1030 control plane employing an NG-C interface. The base station, forexample, the eLTE eNB 1040, may also be interconnected to an NGC 1030user plane (e.g., UPGW) employing an NG-U interface. An NG interface maysupport a many-to-many relation between 5G core networks and basestations.

FIG. 11A, FIG. 11B, FIG. 11C, FIG. 11D, FIG. 11E, and FIG. 11F areexamples for architectures of tight interworking between a 5G RAN and anLTE RAN. The tight interworking may enable a multiplereceiver/transmitter (RX/TX) wireless device in an RRC_CONNECTED stateto be configured to utilize radio resources provided by two schedulerslocated in two base stations (e.g., an eLTE eNB and a gNB). The two basestations may be connected via a non-ideal or ideal backhaul over the Xxinterface between an LTE eNB and a gNB, or over the Xn interface betweenan eLTE eNB and a gNB. Base stations involved in tight interworking fora certain wireless device may assume different roles. For example, abase station may act as a master base station or a base station may actas a secondary base station. In tight interworking, a wireless devicemay be connected to both a master base station and a secondary basestation. Mechanisms implemented in tight interworking may be extended tocover more than two base stations.

A master base station may be an LTE eNB 1102A or an LTE eNB 1102B, whichmay be connected to EPC nodes 1101A or 1101B, respectively. Thisconnection to EPC nodes may be, for example, to an MME via the S1-Cinterface and/or to an S-GW via the S1-U interface. A secondary basestation may be a gNB 1103A or a gNB 1103B, either or both of which maybe a non-standalone node having a control plane connection via an Xx-Cinterface to an LTE eNB (e.g., the LTE eNB 1102A or the LTE eNB 1102B).In the tight interworking architecture of FIG. 11A, a user plane for agNB (e.g., the gNB 1103A) may be connected to an S-GW (e.g., the EPC1101A) through an LTE eNB (e.g., the LTE eNB 1102A), via an Xx-Uinterface between the LTE eNB and the gNB, and via an S1-U interfacebetween the LTE eNB and the S-GW. In the architecture of FIG. 11B, auser plane for a gNB (e.g., the gNB 1103B) may be connected directly toan S-GW (e.g., the EPC 1101B) via an S1-U interface between the gNB andthe S-GW.

A master base station may be a gNB 1103C or a gNB 1103D, which may beconnected to NGC nodes 1101C or 1101D, respectively. This connection toNGC nodes may be, for example, to a control plane core node via the NG-Cinterface and/or to a user plane core node via the NG-U interface. Asecondary base station may be an eLTE eNB 1102C or an eLTE eNB 1102D,either or both of which may be a non-standalone node having a controlplane connection via an Xn-C interface to a gNB (e.g., the gNB 1103C orthe gNB 1103D). In the tight interworking architecture of FIG. 11C, auser plane for an eLTE eNB (e.g., the eLTE eNB 1102C) may be connectedto a user plane core node (e.g., the NGC 1101C) through a gNB (e.g., thegNB 1103C), via an Xn-U interface between the eLTE eNB and the gNB, andvia an NG-U interface between the gNB and the user plane core node. Inthe architecture of FIG. 11D, a user plane for an eLTE eNB (e.g., theeLTE eNB 1102D) may be connected directly to a user plane core node(e.g., the NGC 1101D) via an NG-U interface between the eLTE eNB and theuser plane core node.

A master base station may be an eLTE eNB 1102E or an eLTE eNB 1102F,which may be connected to NGC nodes 1101E or 1101F, respectively. Thisconnection to NGC nodes may be, for example, to a control plane corenode via the NG-C interface and/or to a user plane core node via theNG-U interface. A secondary base station may be a gNB 1103E or a gNB1103F, either or both of which may be a non-standalone node having acontrol plane connection via an Xn-C interface to an eLTE eNB (e.g., theeLTE eNB 1102E or the eLTE eNB 1102F). In the tight interworkingarchitecture of FIG. 11E, a user plane for a gNB (e.g., the gNB 1103E)may be connected to a user plane core node (e.g., the NGC 1101E) throughan eLTE eNB (e.g., the eLTE eNB 1102E), via an Xn-U interface betweenthe eLTE eNB and the gNB, and via an NG-U interface between the eLTE eNBand the user plane core node. In the architecture of FIG. 11F, a userplane for a gNB (e.g., the gNB 1103F) may be connected directly to auser plane core node (e.g., the NGC 1101F) via an NG-U interface betweenthe gNB and the user plane core node.

FIG. 12A, FIG. 12B, and FIG. 12C are examples for radio protocolstructures of tight interworking bearers.

An LTE eNB 1201A may be an S1 master base station, and a gNB 1210A maybe an S1 secondary base station. An example for a radio protocolarchitecture for a split bearer and an SCG bearer is shown. The LTE eNB1201A may be connected to an EPC with a non-standalone gNB 1210A, via anXx interface between the PDCP 1206A and an NR RLC 1212A. The LTE eNB1201A may include protocol layers MAC 1202A, RLC 1203A and RLC 1204A,and PDCP 1205A and PDCP 1206A. An MCG bearer type may interface with thePDCP 1205A, and a split bearer type may interface with the PDCP 1206A.The gNB 1210A may include protocol layers NR MAC 1211A, NR RLC 1212A andNR RLC 1213A, and NR PDCP 1214A. An SCG bearer type may interface withthe NR PDCP 1214A.

A gNB 1201B may be an NG master base station, and an eLTE eNB 1210B maybe an NG secondary base station. An example for a radio protocolarchitecture for a split bearer and an SCG bearer is shown. The gNB1201B may be connected to an NGC with a non-standalone eLTE eNB 1210B,via an Xn interface between the NR PDCP 1206B and an RLC 1212B. The gNB1201B may include protocol layers NR MAC 1202B, NR RLC 1203B and NR RLC1204B, and NR PDCP 1205B and NR PDCP 1206B. An MCG bearer type mayinterface with the NR PDCP 1205B, and a split bearer type may interfacewith the NR PDCP 1206B. The eLTE eNB 1210B may include protocol layersMAC 1211B, RLC 1212B and RLC 1213B, and PDCP 1214B. An SCG bearer typemay interface with the PDCP 1214B.

An eLTE eNB 1201C may be an NG master base station, and a gNB 1210C maybe an NG secondary base station. An example for a radio protocolarchitecture for a split bearer and an SCG bearer is shown. The eLTE eNB1201C may be connected to an NGC with a non-standalone gNB 1210C, via anXn interface between the PDCP 1206C and an NR RLC 1212C. The eLTE eNB1201C may include protocol layers MAC 1202C, RLC 1203C and RLC 1204C,and PDCP 1205C and PDCP 1206C. An MCG bearer type may interface with thePDCP 1205C, and a split bearer type may interface with the PDCP 1206C.The gNB 1210C may include protocol layers NR MAC 1211C, NR RLC 1212C andNR RLC 1213C, and NR PDCP 1214C. An SCG bearer type may interface withthe NR PDCP 1214C.

In a 5G network, the radio protocol architecture that a particularbearer uses may depend on how the bearer is setup. At least threealternatives may exist, for example, an MCG bearer, an SCG bearer, and asplit bearer, such as shown in FIG. 12A, FIG. 12B, and FIG. 12C. The NRRRC may be located in a master base station, and the SRBs may beconfigured as an MCG bearer type and may use the radio resources of themaster base station. Tight interworking may have at least one bearerconfigured to use radio resources provided by the secondary basestation. Tight interworking may or may not be configured or implemented.

The wireless device may be configured with two MAC entities: e.g., oneMAC entity for a master base station, and one MAC entity for a secondarybase station. In tight interworking, the configured set of serving cellsfor a wireless device may comprise of two subsets: e.g., the Master CellGroup (MCG) including the serving cells of the master base station, andthe Secondary Cell Group (SCG) including the serving cells of thesecondary base station.

At least one cell in a SCG may have a configured UL CC and one of them,for example, a PSCell (or the PCell of the SCG, which may also be calleda PCell), is configured with PUCCH resources. If the SCG is configured,there may be at least one SCG bearer or one split bearer. If one or moreof a physical layer problem or a random access problem is detected on aPSCell, if the maximum number of (NR) RLC retransmissions associatedwith the SCG has been reached, and/or if an access problem on a PSCellduring an SCG addition or during an SCG change is detected, then: an RRCconnection re-establishment procedure may not be triggered, ULtransmissions towards cells of the SCG may be stopped, a master basestation may be informed by the wireless device of a SCG failure type,and/or for a split bearer the DL data transfer over the master basestation may be maintained. The RLC AM bearer may be configured for thesplit bearer. Like the PCell, a PSCell may not be de-activated. A PSCellmay be changed with an SCG change, for example, with security key changeand a RACH procedure. A direct bearer type change, between a splitbearer and an SCG bearer, may not be supported. Simultaneousconfiguration of an SCG and a split bearer may not be supported.

A master base station and a secondary base station may interact. Themaster base station may maintain the RRM measurement configuration ofthe wireless device. The master base station may determine to ask asecondary base station to provide additional resources (e.g., servingcells) for a wireless device. This determination may be based on, forexample, received measurement reports, traffic conditions, and/or bearertypes. If a request from the master base station is received, asecondary base station may create a container that may result in theconfiguration of additional serving cells for the wireless device, orthe secondary base station may determine that it has no resourceavailable to do so. The master base station may provide at least part ofthe AS configuration and the wireless device capabilities to thesecondary base station, for example, for wireless device capabilitycoordination. The master base station and the secondary base station mayexchange information about a wireless device configuration such as byusing RRC containers (e.g., inter-node messages) carried in Xn or Xxmessages. The secondary base station may initiate a reconfiguration ofits existing serving cells (e.g., PUCCH towards the secondary basestation). The secondary base station may determine which cell is thePSCell within the SCG. The master base station may not change thecontent of the RRC configuration provided by the secondary base station.If an SCG is added and/or an SCG SCell is added, the master base stationmay provide the latest measurement results for the SCG cell(s). Eitheror both of a master base station and a secondary base station may knowthe SFN and subframe offset of each other by OAM, (e.g., for the purposeof DRX alignment and identification of a measurement gap). If a new SCGSCell is added, dedicated RRC signaling may be used for sending requiredsystem information of the cell, such as for CA, except, for example, forthe SFN acquired from an MIB of the PSCell of an SCG.

FIG. 13A and FIG. 13B show examples for gNB deployment. A core 1301 anda core 1310 may interface with other nodes via RAN-CN interfaces. In anon-centralized deployment example, the full protocol stack (e.g., NRRRC, NR PDCP, NR RLC, NR MAC, and NR PHY) may be supported at one node,such as a gNB 1302, a gNB 1303, and/or an eLTE eNB or LTE eNB 1304.These nodes (e.g., the gNB 1302, the gNB 1303, and the eLTE eNB or LTEeNB 1304) may interface with one of more of each other via a respectiveinter-BS interface. In a centralized deployment example, upper layers ofa gNB may be located in a Central Unit (CU) 1311, and lower layers ofthe gNB may be located in Distributed Units (DU) 1312, 1313, and 1314.The CU-DU interface (e.g., Fs interface) connecting CU 1311 and DUs1312, 1312, and 1314 may be ideal or non-ideal. The Fs-C may provide acontrol plane connection over the Fs interface, and the Fs-U may providea user plane connection over the Fs interface. In the centralizeddeployment, different functional split options between the CU 1311 andthe DUs 1312, 1313, and 1314 may be possible by locating differentprotocol layers (e.g., RAN functions) in the CU 1311 and in the DU 1312,1313, and 1314. The functional split may support flexibility to move theRAN functions between the CU 1311 and the DUs 1312, 1313, and 1314depending on service requirements and/or network environments. Thefunctional split option may change during operation (e.g., after the Fsinterface setup procedure), or the functional split option may changeonly in the Fs setup procedure (e.g., the functional split option may bestatic during operation after Fs setup procedure).

FIG. 14 shows examples for different functional split options of acentralized gNB deployment. Element numerals that are followed by “A” or“B” designations in FIG. 14 may represent the same elements in differenttraffic flows, for example, either receiving data (e.g., data 1402A) orsending data (e.g., 1402B). In the split option example 1, an NR RRC1401 may be in a CU, and an NR PDCP 1403, an NR RLC (e.g., comprising aHigh NR RLC 1404 and/or a Low NR RLC 1405), an NR MAC (e.g., comprisinga High NR MAC 1406 and/or a Low NR MAC 1407), an NR PHY (e.g.,comprising a High NR PHY 1408 and/or a LOW NR PHY 1409), and an RF 1410may be in a DU. In the split option example 2, the NR RRC 1401 and theNR PDCP 1403 may be in a CU, and the NR RLC, the NR MAC, the NR PHY, andthe RF 1410 may be in a DU. In the split option example 3, the NR RRC1401, the NR PDCP 1403, and a partial function of the NR RLC (e.g., theHigh NR RLC 1404) may be in a CU, and the other partial function of theNR RLC (e.g., the Low NR RLC 1405), the NR MAC, the NR PHY, and the RF1410 may be in a DU. In the split option example 4, the NR RRC 1401, theNR PDCP 1403, and the NR RLC may be in a CU, and the NR MAC, the NR PHY,and the RF 1410 may be in a DU. In the split option example 5, the NRRRC 1401, the NR PDCP 1403, the NR RLC, and a partial function of the NRMAC (e.g., the High NR MAC 1406) may be in a CU, and the other partialfunction of the NR MAC (e.g., the Low NR MAC 1407), the NR PHY, and theRF 1410 may be in a DU. In the split option example 6, the NR RRC 1401,the NR PDCP 1403, the NR RLC, and the NR MAC may be in CU, and the NRPHY and the RF 1410 may be in a DU. In the split option example 7, theNR RRC 1401, the NR PDCP 1403, the NR RLC, the NR MAC, and a partialfunction of the NR PHY (e.g., the High NR PHY 1408) may be in a CU, andthe other partial function of the NR PHY (e.g., the Low NR PHY 1409) andthe RF 1410 may be in a DU. In the split option example 8, the NR RRC1401, the NR PDCP 1403, the NR RLC, the NR MAC, and the NR PHY may be ina CU, and the RF 1410 may be in a DU.

The functional split may be configured per CU, per DU, per wirelessdevice, per bearer, per slice, and/or with other granularities. In a perCU split, a CU may have a fixed split, and DUs may be configured tomatch the split option of the CU. In a per DU split, each DU may beconfigured with a different split, and a CU may provide different splitoptions for different DUs. In a per wireless device split, a gNB (e.g.,a CU and a DU) may provide different split options for differentwireless devices. In a per bearer split, different split options may beutilized for different bearer types. In a per slice splice, differentsplit options may be applied for different slices.

A new radio access network (new RAN) may support different networkslices, which may allow differentiated treatment customized to supportdifferent service requirements with end to end scope. The new RAN mayprovide a differentiated handling of traffic for different networkslices that may be pre-configured, and the new RAN may allow a singleRAN node to support multiple slices. The new RAN may support selectionof a RAN part for a given network slice, for example, by one or moreslice ID(s) or NSSAI(s) provided by a wireless device or provided by anNGC (e.g., an NG CP). The slice ID(s) or NSSAI(s) may identify one ormore of pre-configured network slices in a PLMN. For an initial attach,a wireless device may provide a slice ID and/or an NSSAI, and a RAN node(e.g., a gNB) may use the slice ID or the NSSAI for routing an initialNAS signaling to an NGC control plane function (e.g., an NG CP). If awireless device does not provide any slice ID or NSSAI, a RAN node maysend a NAS signaling to a default NGC control plane function. Forsubsequent accesses, the wireless device may provide a temporary ID fora slice identification, which may be assigned by the NGC control planefunction, to enable a RAN node to route the NAS message to a relevantNGC control plane function. The new RAN may support resource isolationbetween slices. If the RAN resource isolation is implemented, shortageof shared resources in one slice does not cause a break in a servicelevel agreement for another slice.

The amount of data traffic carried over networks is expected to increasefor many years to come. The number of users and/or devices isincreasing, and each user/device accesses an increasing number andvariety of services, for example, video delivery, large files, andimages. This requires not only high capacity in the network, but alsoprovisioning very high data rates to meet customers' expectations oninteractivity and responsiveness. More spectrum may be required fornetwork operators to meet the increasing demand Considering userexpectations of high data rates along with seamless mobility, it isbeneficial that more spectrum be made available for deploying macrocells as well as small cells for communication systems.

Striving to meet the market demands, there has been increasing interestfrom operators in deploying some complementary access utilizingunlicensed spectrum to meet the traffic growth. This is exemplified bythe large number of operator-deployed Wi-Fi networks and the 3GPPstandardization of LTE/WLAN interworking solutions. This interestindicates that unlicensed spectrum, if present, may be an effectivecomplement to licensed spectrum for network operators, for example, tohelp address the traffic explosion in some examples, such as hotspotareas. Licensed Assisted Access (LAA) offers an alternative foroperators to make use of unlicensed spectrum, for example, if managingone radio network, offering new possibilities for optimizing thenetwork's efficiency.

Listen-before-talk (clear channel assessment) may be implemented fortransmission in an LAA cell. In a listen-before-talk (LBT) procedure,equipment may apply a clear channel assessment (CCA) check before usingthe channel. For example, the CCA may utilize at least energy detectionto determine the presence or absence of other signals on a channel todetermine if a channel is occupied or clear, respectively. For example,European and Japanese regulations mandate the usage of LBT in theunlicensed bands. Apart from regulatory requirements, carrier sensingvia LBT may be one way for fair sharing of the unlicensed spectrum.

Discontinuous transmission on an unlicensed carrier with limited maximumtransmission duration may be enabled. Some of these functions may besupported by one or more signals to be transmitted from the beginning ofa discontinuous LAA downlink transmission. Channel reservation may beenabled by the transmission of signals, by an LAA node, after gainingchannel access, for example, via a successful LBT operation, so thatother nodes that receive the transmitted signal with energy above acertain threshold sense the channel to be occupied. Functions that mayneed to be supported by one or more signals for LAA operation withdiscontinuous downlink transmission may include one or more of thefollowing: detection of the LAA downlink transmission (including cellidentification) by wireless devices, time synchronization of wirelessdevices, and frequency synchronization of wireless devices.

DL LAA design may employ subframe boundary alignment according to LTE-Acarrier aggregation timing relationships across serving cells aggregatedby CA. This may not indicate that the eNB transmissions may start onlyat the subframe boundary. LAA may support transmitting PDSCH if not allOFDM symbols are available for transmission in a subframe according toLBT. Delivery of necessary control information for the PDSCH may also besupported.

LBT procedures may be employed for fair and friendly coexistence of LAAwith other operators and technologies operating in unlicensed spectrum.LBT procedures on a node attempting to transmit on a carrier inunlicensed spectrum may require the node to perform a clear channelassessment to determine if the channel is free for use. An LBT proceduremay involve at least energy detection to determine if the channel isbeing used. For example, regulatory requirements in some regions, forexample, in Europe, specify an energy detection threshold such that if anode receives energy greater than this threshold, the node assumes thatthe channel is not free. Nodes may follow such regulatory requirements.A node may optionally use a lower threshold for energy detection thanthat specified by regulatory requirements. LAA may employ a mechanism toadaptively change the energy detection threshold, for example, LAA mayemploy a mechanism to adaptively change (e.g., lower or increase) theenergy detection threshold from an upper bound. Adaptation mechanism maynot preclude static or semi-static setting of the threshold. A Category4 LBT mechanism or other type of LBT mechanisms may be implemented.

Various example LBT mechanisms may be implemented. For some signals, insome implementation scenarios, in some situations, and/or in somefrequencies, no LBT procedure may performed by the transmitting entity.Category 2 (e.g., LBT without random back-off) may be implemented. Theduration of time that the channel is sensed to be idle before thetransmitting entity transmits may be deterministic. Category 3 (e.g.,LBT with random back-off with a contention window of fixed size) may beimplemented. The LBT procedure may have the following procedure as oneof its components. The transmitting entity may draw a random number Nwithin a contention window. The size of the contention window may bespecified by the minimum and maximum value of N. The size of thecontention window may be fixed. The random number N may be employed inthe LBT procedure to determine the duration of time that the channel issensed to be idle, for example, before the transmitting entity transmitson the channel Category 4 (e.g., LBT with random back-off with acontention window of variable size) may be implemented. The transmittingentity may draw a random number N within a contention window. The sizeof contention window may be specified by the minimum and maximum valueof N. The transmitting entity may vary the size of the contention windowif drawing the random number N. The random number N may be used in theLBT procedure to determine the duration of time that the channel issensed to be idle, for example, before the transmitting entity transmitson the channel.

LAA may employ uplink LBT at the wireless device. The UL LBT scheme maybe different from the DL LBT scheme, for example, by using different LBTmechanisms or parameters. These differences in schemes may be due to theLAA UL being based on scheduled access, which may affect a wirelessdevice's channel contention opportunities. Other considerationsmotivating a different UL LBT scheme may include, but are not limitedto, multiplexing of multiple wireless devices in a single subframe.

LAA may use uplink LBT at the wireless device. The UL LBT scheme may bedifferent from the DL LBT scheme, for example, by using different LBTmechanisms or parameters. These differences in schemes may be due to theLAA UL being based on scheduled access, which may affect a wirelessdevice's channel contention opportunities. Other considerationsmotivating a different UL LBT scheme may include, but are not limitedto, multiplexing of multiple wireless devices in a single subframe.

A DL transmission burst may be a continuous transmission from a DLtransmitting node, for example, with no transmission immediately beforeor after from the same node on the same CC. An UL transmission burstfrom a wireless device perspective may be a continuous transmission froma wireless device, for example, with no transmission immediately beforeor after from the same wireless device on the same CC. A UL transmissionburst may be defined from a wireless device perspective or from a basestation perspective. If a base station is operating DL and UL LAA overthe same unlicensed carrier, DL transmission burst(s) and ULtransmission burst(s) on LAA may be scheduled in a TDM manner over thesame unlicensed carrier. An instant in time may be part of a DLtransmission burst or part of an UL transmission burst.

A wireless device configured for operation with wireless resources(e.g., bandwidth parts (BWPs)) of a serving cell may be configured byhigher layers for the serving cell. The wireless device may beconfigured for a set of BWPs for receptions by the wireless device(e.g., DL BWP set) and/or or a set of BWPs for transmissions by thewireless device (e.g., UL BWP set). For a DL BWP, an UL BWP in a set ofDL BWPs, or an UL BWPs, the wireless device may be configured with atleast one of following for the serving cell: a subcarrier spacing (SCS)for DL BWP and/or UL BWP, a cyclic prefix (CP) for DL BWP and/or UL BWP,a number of contiguous PRBs for DL BWP and/or UL BWP, an offset of thefirst PRB of DL BWP and/or UL BWP in the number of contiguous PRBsrelative to the first PRB of a reference location, and/or Q controlresource sets (e.g., if the BWP is a DL BWP). Higher layer signaling mayconfigure a wireless device with Q control resource sets, for example,for each serving cell. For a control resource set q, such that 0≤q<Q theconfiguration may comprise one or more of following: a first OFDMsymbol, a number of consecutive OFDM symbols, a set of resource blocks,a CCE-to-REG mapping, a REG bundle size (e.g., for interleavedCCE-to-REG mapping), and/or antenna port quasi-collocationBWP.

A control resource set may comprise a set of CCEs numbered from 0 toN_(CCE,q)−1 where N_(CCE,q) may be the number of CCEs in controlresource set q. Sets of PDCCH candidates that a wireless device monitorsmay be defined in terms of PDCCH wireless device-specific search spaces.A PDCCH wireless device-specific search space at CCE aggregation levelL∈{1, 2, 4, 8} may be defined by a set of PDCCH candidates for CCEaggregation level L. A wireless device may be configured (e.g., for aDCI format), per serving cell by one or more higher layer parameters,for a number of PDCCH candidates per CCE aggregation level L.

A wireless device may monitor (e.g., in non-DRX mode operation) one ormore PDCCH candidate in control resource set q according to aperiodicity of W_(PDCCH) _(q) symbols. The symbols may be configured byone or more higher layer parameters for control resource set q. Thecarrier indicator field value may correspond to cif-InSchedulingCell,for example, if a wireless device is configured with a higher layerparameter (e.g., cif-InSchedulingCell). For the serving cell on which awireless device may monitor one or more PDCCH candidate in a wirelessdevice-specific search space, the wireless device may monitor the one ormore PDCCH candidates without carrier indicator field (e.g., if thewireless device is not configured with a carrier indicator field). Forthe serving cell on which a wireless device may monitor one or morePDCCH candidates in a wireless device-specific search space, thewireless device may monitor the one or more PDCCH candidates withcarrier indicator field (e.g., if a wireless device is configured with acarrier indicator field). A wireless device may not monitor one or morePDCCH candidates on a secondary cell, for example, if the wirelessdevice is configured to monitor one or more PDCCH candidates withcarrier indicator field corresponding to that secondary cell in anotherserving cell. For the serving cell on which the wireless device maymonitor one or more PDCCH candidates, the wireless device may monitorthe one or more PDCCH candidates at least for the same serving cell.

A wireless device may receive PDCCH and PDSCH in a DL BWP according to aconfigured SCS and CP length for the DL BWP. A wireless device maytransmit PUCCH and/or PUSCH in an UL BWP according to a configured SCSand CP length for the UL BWP.

A wireless device may be configured, by one or more higher layerparameters, for a DL BWP from a configured DL BWP set for DL receptions.A wireless device may be configured, by one or more higher layerparameters, for an UL BWP from a configured UL BWP set for ULtransmissions. A DL BWP index field value may indicate a DL BWP (such asfrom the configured DL BWP set) for DL receptions, for example, if theDL BWP index field is configured in a DCI format scheduling PDSCHreception to a wireless device. An UL-BWP index field value may indicatethe UL BWP (such as from the configured UL BWP set) for ULtransmissions, for example, if the UL-BWP index field is configured in aDCI format scheduling PUSCH transmission from a wireless device.

A wireless device may determine that the center frequency for the DL BWPis or should be the same as the center frequency for the UL BWP, such asfor TDD. The wireless device may not monitor PDCCH, for example, if thewireless device performs measurements over a bandwidth that is notwithin the DL BWP for the wireless device.

A wireless device may identify the bandwidth and/or frequency of aninitial active DL BWP, such as for an initial active DL BWP. Thewireless device may identify the bandwidth and/or frequency after or inresponse to receiving the NR-PBCH. A bandwidth of an initial active DLBWP may be confined within the wireless device minimum bandwidth for thegiven frequency band. The bandwidth may be indicated in PBCH, such asfor flexible DL information scheduling. Some bandwidth candidates may bepredefined. A number of bits (e.g., x bits) may be used for a bandwidthindication.

A frequency location of an initial active DL BWP may be derived from thebandwidth and SS block (e.g., a center frequency of the initial activeDL BWP). The edge of the SS block PRB and data PRB boundary may not bealigned. An SS block may have a frequency offset, for example, if theedge of the SS block PRB and data PRB are not aligned. Predefining thefrequency location of an SS block and an initial active DL BWP mayreduce the PBCH payload size such that additional bits may not be neededfor an indication of a frequency location of an initial active DL BWP.The bandwidth and frequency location may be informed in RMSI, forexample, for the paired UL BWP.

A base station may configure a set of BWPs for a wireless device by RRCsignaling. The wireless device may transmit or receive in an active BWPfrom the configured BWPs in a given time instance. Activation and/or adeactivation of DL bandwidth part may be based on a timer for a wirelessdevice. The wireless device may switch its active DL bandwidth part to adefault DL bandwidth part, for example, if a timer expires. If thewireless device has not received scheduling DCI for a time period (e.g.,X ms, or after expiry of a timer), the wireless device may switch to thedefault DL BWP.

A new timer (e.g., BWPDeactivationTimer) may be defined to deactivatethe original BWP and/or switch to the default BWP. The new timer (e.g.,BWPDeactivationTimer) may be started if the original BWP is activated bythe activation and/or deactivation DCI. If PDCCH on the original BWP isreceived, a wireless device may restart the timer (e.g.,BWPDeactivationTimer) associated with the original BWP. If the timer(e.g., BWPDeactivationTimer) expires, a wireless device may deactivatethe original BWP, switch to the default BWP, stop the timer for theoriginal BWP, and/or flush (or not flush) all HARQ buffers associatedwith the original BWP.

A base station and a wireless device may have a different understandingof the starting of the timer, for example, if the wireless device missesone or more scheduling grants. The wireless device may be triggered toswitch to the default BWP, but the base station may schedule thewireless device in the previous active BWP. The base station mayrestrict the location of the CORESET of BWP2 to be within BWP1 (e.g.,the narrow band BWP1 may be the default BWP), for example, if thedefault BWP is nested within other BWPs. The wireless device may receivean indication (e.g., CORESET) and switch back to BWP2, for example, ifthe wireless device previously mistakenly switched to the default BWP.

Restricting the location of the indication (e.g., CORESET) may not solvea miss switching problem, for example, if the default BWP and the otherBWPs are not overlapped in frequency domain. The base station maymaintain a timer for a wireless device. If the timer expires (e.g., ifthere is no data scheduled for the wireless device for a time periodsuch as Y ms), and/or if the base station has not received feedback fromthe wireless device for a time period (such as Y′ ms), the wirelessdevice may switch to the default BWP. The wireless device may switch tothe default BWP to send a paging signal and/or to re-schedule thewireless device in the default BWP.

A base station may not fix the default BWP to be the same as an initialactive BWP. The initial active DL BWP may be the SS block bandwidthwhich is common to wireless devices in the cell. The traffic load may bevery heavy, for example, if many wireless devices fall back to a smallbandwidth for data transmission. Configuring the wireless devices withdifferent default BWPs may help to balance the load in the systembandwidth.

There may be no initial active BWP on an SCell, for example, if theinitial access is performed on the PCell. An DL BWP and/or UL BWP thatis initially activated based on the SCell being activated may beconfigured or reconfigured by RRC signaling. The default BWP of theSCell may also be configured and/or reconfigured by RRC signaling. Thedefault BWP may be configured or reconfigured by the RRC signaling,and/or the default BWP may be one of the configured BWPs of the wirelessdevice, which may provide a unified design for both PCell and SCell.

The base station may configure a wireless device-specific default DL BWPother than an initial active BWP. The base station may configure thewireless device-specific default DL BWP, for example, after RRCconnection, which may be performed for the purpose of load balancing.The default BWP may support connected mode operations other thanoperations supported by initial active BWP. Other connected modeoperations may comprise, for example, fall back and/or connected modepaging. The default BWP may comprise a common search space, such as atleast the search space needed for monitoring the pre-emptionindications. The default DL and UL BWPs may be independently configuredto the wireless device, such as for FDD.

The initial active DL BWP and/or UL BWP may be set as default DL BWPand/or UL BWP, respectively. A wireless device may return to default DLBWP and/or UL BWP. For example, if a wireless device does not receivecontrol for a long time (e.g., based on a timer expiration or a timeduration reaching a threshold), the wireless device may fall back to adefault BWP (e.g., default DL BWP and/or default UL BWP).

A base station may configure a wireless device with multiple BWPs. Themultiple BWPs may share at least one CORESET including a default BWP.CORESET for RMSI may be shared for all configured BWPs. The wirelessdevice may receive control information via the common CORESET, forexample, without going back to another BWP or a default BWP. The commonCORESET may schedule data within only a default BWP, which may minimizethe ambiguity of resource allocation, for example, if a frequency regionof a default BWP may belong to all or more than one of the configuredBWPs.

A semi-static pattern of BWP switching to default BWP may be performed,for example, if the configured BWP is associated with a differentnumerology from a default BWP. Switching to a default BWP may beperformed, for example, to check RMSI at least periodically. Switchingto a default BWP may be necessary particularly if BWPs use differentnumerologies.

Reconfiguration of a default BWP from an initial BWP may be performed,such as for RRC connected wireless devices. A default BWP may be thesame as an initial BWP, such as for RRC IDLE wireless devices.Additionally or alternatively, a wireless device (e.g., RRC IDLEwireless device) may fall back to an initial BWP regardless of a defaultBWP. If a wireless device performs a measurement based on SS block,reconfiguration of a default BWP outside of an initial BWP may becomevery inefficient, for example, due to frequent measurement gaps. If adefault BWP is reconfigured to outside of an initial BWP, the followingconditions may be satisfied: a wireless device may be in a CONNECTEDmode, and/or a wireless device may not be configured with an SS blockbased measurement for both serving cell and neighbor cells.

A DL BWP other than the initial active DL BWP may be configured as thedefault DL BWP for a wireless device. Reconfiguring the default DL BWPmay be performed based on load balancing and/or different numerologiesused for an active DL BWP and an initial active DL BWP. A default BWP ona PCell may be an initial active DL BWP for a transmission of RMSI. Thetransmission of RMSI may comprise one or more of an RMSI CORESET with aCSS, and/or a wireless device-specific search space (e.g., USS). Theinitial active BWP and/or default BWP may remain an active BWP for auser after a wireless device becomes RRC connected.

Downlink and uplink BWPs may be independently activated, such as for apaired spectrum. Downlink and uplink bandwidth parts may be jointlyactivated, such as for an unpaired spectrum. In bandwidth adaptation(e.g., where the bandwidth of the active downlink BWP may be changed), ajoint activation of a new downlink BWP and a new uplink BWP may beperformed (e.g., for an unpaired spectrum). A new DL/UL BWP pair may beactivated such that the bandwidth of the uplink BWPs may be the same(e.g., there may not be a change of an uplink BWP).

There may be an association of DL BWP and UL BWP in RRC configuration.For example, a wireless device may not retune the center frequency of achannel bandwidth (BW) between DL and UL, such as for TDD. If the RF isshared between DL and UL (e.g., in TDD), a wireless device may notretune the RF BW for every alternating DL-to-UL and UL-to-DL switching.

Applying an association between a DL BWP and an UL BWP may enable anactivation and/or deactivation command to switch both DL and UL BWPs.Such switching may comprise switching a DL BWP together with switchingan UL BWP. If an association is not applied between a DL BWP and an ULBWP, separate BWP switching commands may be necessary.

A DL BWP and an UL BWP may be configured separately for the wirelessdevice. Pairing of the DL BWP and the UL BWP may impose constraints onthe configured BWPs (e.g., the paired DL BWP and UL BWP may be activatedsimultaneously or near simultaneously such as within a threshold timeperiod). A base station may indicate a DL BWP and an UL BWP to awireless device for activation, for example, in a FDD system. A basestation may indicate to a wireless device a DL BWP and an UL BWP withthe same center frequency for activation, for example, in a TDD system.No pairing and/or association of the DL BWP and UL BWP may be mandatory,even for TDD system, for example, if the activation and/or deactivationof the BWP for the wireless device is instructed by the base station.Pairing and/or association of the DL BWP and UL BWP may be determined bya base station.

An association between a DL carrier and an UL carrier within a servingcell may be performed by carrier association. A wireless device may notbe expected to retune the center frequency of a channel BW between DLand UL, such as for a TDD system. An association between a DL BWP and anUL BWP may be required for a wireless device. An association may beperformed by grouping DL BWP configurations with same center frequencyas one set of DL BWPs and grouping UL BWP configurations with samecenter frequency as one set of UL BWPs. The set of DL BWPs may beassociated with the set of UL BWPs sharing the same center frequency.There may be no association between a DL BWP and an UL BWP, for example,if the association between a DL carrier and an UL carrier within aserving cell may performed by carrier association, such as for an FDDserving cell.

A wireless device may identify a BWP identity from a DCI, which maysimplify an indication process. The total number of bits for a BWPidentity may depend on the number of bits that may be used within ascheduling DCI (and/or a switching DCI), and/or the wireless deviceminimum BW. The number of BWPs may be determined based on the wirelessdevice supported minimum BW and/or the network maximum BW. The maximumnumber of BWPs may be determined based on the network maximum BW and/orthe wireless device minimum BW. For example, if 400 MHz is the networkmaximum BW and 50 MHz is the wireless device minimum BW, 8 BWPs may beconfigured to the wireless device such that 3 bits may be requiredwithin the DCI to indicate the BWP. Such a split of the network BW(e.g., depending on the wireless device minimum BW) may be useful forcreating one or more default BWPs from the network side by distributingwireless devices across the entire network BW (e.g., for load balancingpurposes).

At least two DL and two UL BWPs may be supported by a wireless devicefor a BWP adaption. The total number of BWPs supported by a wirelessdevice may be given by 2≤number of DL/UL BWP≤floor (network maximumBW/wireless device minimum DL/UL BW), where floor(x) may be a floorfunction that returns the greatest integer being less than or equal tox. For example, a maximum number of configured BWPs may be four for DLand UL, respectively, or a maximum number of configured BWPs for UL maybe two. Any other number of BWPs, for example, greater than or equal to2 and less than or equal to a floor, may be supported by a wirelessdevice.

Different sets of BWPs may be configured for different DCI formatsand/or scheduling types, respectively. BWPs may be configured fornon-slot-based scheduling (e.g., for larger BWPs) or for slot-basedscheduling (e.g., for smaller BWPs). If different DCI formats aredefined for slot-based scheduling and non-slot-based scheduling,different BWPs may be configured for different DCI formats. DifferentBWP configurations may provide flexibility between different schedulingtypes without increasing DCI overhead. A 2-bit field may be used toindicate a BWP among four BWPs for a DCI format. For example, four DLBWPs or two or four UL BWPs may be configured for each DCI format. Thesame or different BWPs may be configured for different DCI formats.

A required maximum number of configured BWPs (which may exclude theinitial BWP) may depend on the flexibility needed for a BWPfunctionality. It may be sufficient to be able to configure one DL BWPand one UL BWP (or a single DL/UL BWP pair for an unpaired spectrum),which may correspond to minimal support of bandlimited devices. Theremay be a need to configure at least two DL BWPs and at least a singleuplink BWP for a paired spectrum (or two DL/UL BWP pairs for an unpairedspectrum), such as to support bandwidth adaptation. There may be a needto configure one or more DL (or UL) BWPs that jointly cover differentparts of the downlink (or uplink) carrier, such as to support dynamicload balancing between different parts of the spectrum. Two BWPs may besufficient, for example, for dynamic load balancing. In addition to thetwo BWPs, two other BWPs may be needed, such as for bandwidthadaptation. A maximum number of configured BWPs may be four DL BWPs andtwo UL BWPs for a paired spectrum. A maximum number of configured BWPsmay be four DL/UL BWP pairs for an unpaired spectrum.

A wireless device may monitor for RMSI and broadcasted OSI, which may betransmitted by a base station within a common search space (CSS) on thePCell. RACH response and paging control monitoring on the PCell may betransmitted within the CSS. A wireless device may not monitor the commonsearch space, for example, if the wireless device is allowed to be on anactive BWP configured with a wireless device-specific search space (USSSor USS).

At least one of configured DL bandwidth parts may comprise at least oneCORESET with a CSS type, such as for a PCell. To monitor RMSI andbroadcast OSI, the wireless device may periodically switch to the BWPcontaining the CSS. The wireless device may periodically switch to theBWP containing the CSS for RACH response and paging control monitoringon the PCell.

BWP switching to monitor the CSS may result in increasing overhead, forexample, if the BWP switching occurs frequently. The overhead due to theCSS monitoring may depend on an overlapping in frequency between any twoBWPs. In a nested BWP configuration (e.g., where one BWP may be a subsetof another BWP), the same CORESET configuration may be used across theBWPs. A default BWP may comprise the CSS, and another BWP may comprisethe CSS, for example, if the default BWP is a subset of another BWP. TheBWPs may be partially overlapping. A CSS may be across a first BWP and asecond BWP, for example, if the overlapping region is sufficient. Twonon-overlapping BWP configurations may exist.

There may be one or more benefits from configuring the same CORESETcontaining the CSS across BWPs. For example, the RMSI and broadcast OSImonitoring may be performed without necessitating BWP switching, RACHresponse and paging control monitoring on the PCell may be performedwithout switching, and/or robustness for BWP switching may improve. Abase station and a wireless device may be out-of-sync as to which BWP iscurrently active and the DL control channel may still work, for example,if CORESET configuration is the same across BWPs. One or moreconstraints on BWP configuration may be acceptable. A BWP may providepower saving, such that various configurations, including a nestedconfiguration, may be very versatile for different applications.

Group-common search space (GCSS) may be supported (e.g., in NR). TheGCSS may be used in addition to or as an alternative to CSS for certaininformation. A base station may configure GCSS within a BWP for awireless device. Information such as RACH response and paging controlmay be transmitted on GCSS. The wireless device may monitor GCSS, forexample, instead of switching to the BWP containing the CSS for suchinformation. A base station may transmit information on GCSS, forexample, for a pre-emption indication and other group-based commands ona serving cell. A wireless device may monitor the GCSS for theinformation (e.g., for the SCell which may not have CSS).

A CORESET may be configured without using a BWP. The CORESET may beconfigured based on a BWP, which may reduce signaling overhead. A firstCORESET for a wireless device during an initial access may be configuredbased on a default BWP. A CORESET for monitoring PDCCH for RAR andpaging may be configured based on a DL BWP. The CORESET for monitoringgroup common (GC)-PDCCH for SFI may be configured based on a DL BWP. TheCORESET for monitoring GC-DCI for a pre-emption indication may beconfigured based on a DL BWP. A BWP index may be indicated in theCORESET configuration. A default BWP index may not be indicated in theCORESET configuration.

A contention-based random access (CBRA) RACH procedure may be supportedvia an initial active DL BWP and/or an initial active UL BWP, forexample, if the wireless device identity is unknown to the base station.The contention-free random access (CFRA) RACH procedure may be supportedvia the USS configured in an active DL BWP for the wireless device. Anadditional CSS for RACH purposes may not need to be configured per BWP,such as for the CFRA RACH procedure supported via the USS configured inan active DL BWP for the wireless device. Idle mode paging may besupported via an initial active DL BWP. Connected mode paging may besupported via a default BWP. No additional configurations for the BWPfor paging purposes may be needed for paging. A configured BWP (e.g., ona serving cell) may have the CSS configured for monitoring pre-emptionindications for a pre-emption.

A group-common search space may be associated with at least one CORESETconfigured for the same DL BWP (e.g., for a configured DL BWP). Thewireless device may or may not autonomously switch to a default BWP(e.g., where a group-common search space may be available) to monitorfor a DCI, for example, depending on the monitoring periodicity ofdifferent group-common control information types. A group-common searchspace may be configured in the same CORESET, for example, if there is atleast one CORESET configured on a DL BWP.

A center frequency of an activated DL BWP may or may not be changed. Ifthe center frequency of the activated DL BWP and the deactivated DL BWPis not aligned, the active UL BWP may be switched implicitly (e.g., forTDD).

BWPs with different numerologies may be overlapped. Rate matching forCSI-RS and/or SRS of another BWP in the overlapped region may beperformed, which may achieve dynamic resource allocation of differentnumerologies in a FDM and/or a TDM manner. For a CSI measurement withinone BWP, if the CSI-RS and/or SRS collides with data and/or an RS inanother BWP, the collision region in another BWP may be rate matched.CSI information over the two or more BWPs may be determined by a basestation based on wireless device reporting. Dynamic resource allocationwith different numerologies in a FDM manner may be achieved by basestation scheduling.

PUCCH resources may be configured in a configured UL BWP, in a defaultUL BWP, and/or in both a configured UL BWP and a default UL BWP. If thePUCCH resources are configured in the default UL BWP, a wireless devicemay retune to the default UL BWP for transmitting an SR. The PUCCHresources may be configured per a default BWP or per a BWP other thanthe default BWP. The wireless device may transmit an SR in the currentactive BWP without retuning. If a configured SCell is activated for awireless device, a DL BWP may be associated with an UL BWP at least forthe purpose of PUCCH transmission, and/or a default DL BWP may beactivated. If the wireless device is configured for UL transmission inthe same serving cell, a default UL BWP may be activated.

At least one of configured DL BWPs may comprise one CORESET with commonsearch space (CSS), for example, at least in a primary componentcarrier. The CSS may be needed at least for RACH response (e.g., a msg2)and/or a pre-emption indication. One or more of configured DL bandwidthparts for a PCell may comprise a CORESET with the CSS type for RMSIand/or OSI, for example, if there is no periodic gap for RACH responsemonitoring on the PCell. A configured DL BWP for a PCell may compriseone CORESET with the CSS type for RACH response and paging control for asystem information update. A configured DL BWP for a serving cell maycomprise a CORESET with the CSS type for a pre-emption indication and/orother group-based commands.

BWPs may be configured with respect to common reference point (e.g., PRB0) on a component carrier. The BWPs may be configured using TYPE1 RA asa set of contiguous PRBs, with PRB granularity for the START and LENGTH.The minimum length may be determined by the minimum supported size of aCORESET. A CSS may be configured on a non-initial BWP, such as for RARand paging.

To monitor common channel or group common channel for a connectedwireless device (e.g., RRC CONNECTED UE), an initial DL BWP may comprisea control channel for RMSI, OSI, and/or paging. The wireless device mayswitch a BWP to monitor such a control channel A configured DL BWP maycomprise a control channel (e.g., for a Msg2). A configured DL BWP maycomprise a control channel for a SFI. A configured DL BWP may comprise apre-emption indication and/or other group common indicators such as forpower control.

A DCI may explicitly indicate activation and/or deactivation of a BWP. ADCI without data assignment may comprise an indication to activateand/or deactivate BWP. A wireless device may receive a first indicationvia a first DCI to activate and/or deactivate a BWP. A second DCI with adata assignment may be transmitted by the base station, for example, fora wireless device to start receiving data. The wireless device mayreceive the first DCI in a target CORESET within a target BWP. A basestation scheduler may make conservative scheduling decisions, forexample, until the base station receives CSI feedback.

A DCI without scheduling for active BWP switching may be transmitted,for example, to measure the CSI before scheduling. A DCI with schedulingfor active BWP switching may comprise setting the resource allocationfield to zero, such that no data may be scheduled. Other fields in theDCI may comprise one or more CSI and/or SRS request fields.

Single scheduling a DCI to trigger active BWP switching may providedynamic BWP adaptation for wireless device power saving during activestate. Wireless device power saving during active state may occur for anON duration, and/or if an inactivity timer is running and/or if C-DRX isconfigured. A wireless device may consume a significant amount of powermonitoring PDCCH, without decoding any grant, for example if a C-DRX isenabled. To reduce the power consumption during PDCCH monitoring, twoBWPs may be configured: a narrower BWP for PDCCH monitoring, and a widerBWP for scheduled data. The wireless device may switch back-and-forthbetween the narrower BWP and the wider BWP, depending on the burstinessof the traffic. The wireless device may revisit a BWP that it haspreviously used. Combining a BWP switching indication and a schedulinggrant may provide an advantage of low latency and/or reduced signalingoverhead for BWP switching.

An SCell activation and/or deactivation may or may not trigger acorresponding action for its configured BWP. A dedicated BWP activationand/or deactivation DCI may impact a DCI format. A scheduling DCI with adummy grant may be used. The dummy grant may be constructed byinvalidating one or some of the fields, such as the resource allocationfield. A fallback scheduling DCI format (which may contain a smallerpayload) may be used, which may improve the robustness for BWP DCIsignaling without incurring extra work by introducing a new DCI format.

A DCI with data assignment may comprise an indication to activate and/ordeactivate a BWP along with a data assignment. A wireless device mayreceive a combined data allocation and BWP activation and/ordeactivation message. A DCI format may comprise a field to indicate BWPactivation and/or deactivation and/or a field indicating an UL grantand/or a DL grant. The wireless device may start receiving data with asingle DCI, such as the DCI format described above. The DCI may indicateone or more target resources of a target BWP. A base station schedulermay have insufficient information about the CSI in the target BW and maymake conservative scheduling decisions.

The DCI may be transmitted on a current active BWP, and schedulinginformation may be for a new BWP, for example, for the DCI with dataassignment. There may be a single active BWP. There may be one DCI in aslot for scheduling the current BWP or scheduling another BWP. The sameCORESET may be used for the DCI scheduling of the current BWP and theDCI scheduling of another BWP. The DCI payload size for the DCIscheduling current BWP and the scheduling DCI for BWP switching may bethe same, which may reduce the number of blind decoding attempts.

In A BWP group may be configured by a base station, in which anumerology in one group may be the same, which may support using thescheduling DCI for BWP switching. The BWP switching for the BWP groupmay be configured, such that BIF may be present in the CORESETs for oneor more BWPs in the group. Scheduling DCI for BWP switching may beconfigured per BWP group, in which an active BWP in the group may beswitched to any other BWP in the group.

A DCI comprising a scheduling assignment and/or grant may not comprisean active-BWP indicator. A scheduling DCI may switch a wireless devicesactive BWP to the transmission direction for which the scheduling isvalid (e.g., for a paired spectrum). A scheduling DCI may switch thewireless devices active DL/UL BWP pair regardless of the transmissiondirection for which the scheduling is valid (e.g., for an unpairedspectrum). A downlink scheduling assignment and/or grant with noassignment may occur, which may allow for a switching of an active BWPwithout scheduling downlink and/or uplink transmissions.

A timer-based activation and/or deactivation BWP may be supported. Atimer for activation and/or deactivation of DL BWP may reduce signalingoverhead and may allow wireless device power savings. The activationand/or deactivation of a DL BWP may be based on an inactivity timer,which may be referred to as a BWP inactive (or inactivity) timer. Awireless device may start and/or reset a timer upon reception of a DCI.The timer may expire, for example, if the wireless device is notscheduled for the duration of the timer. The wireless device mayactivate and/or deactivate the appropriate BWP based on the expiry ofthe timer. The wireless device may, for example, activate the defaultBWP and/or deactivate the active BWP.

A BWP inactive timer may be beneficial for power saving for a wirelessdevice. A wireless device may reduce power, for example, by switching toa default BWP with a smaller bandwidth. A wireless device may use a BWPinactive timer, for example, for a fallback if missing a DCI basedactivation and/or deactivation signaling, such as by switching from oneBWP to another BWP. Triggering conditions of the BWP inactive timer mayfollow triggering conditions for the DRX timer in LTE or any othersystem. An on-duration of the BWP inactive timer may be configuredand/or the timer may start, for example, if a wireless device-specificPDCCH is successfully decoded indicating a new transmission during theon-duration. The timer may restart, for example, if a wirelessdevice-specific PDCCH is successfully decoded indicating a newtransmission. The timer may stop, for example, if the wireless device isscheduled to switch to the default DL BWP. The BWP inactive timer maystart, for example, if the wireless device switches to a new DL BWP. Thetimer may restart, for example, if a wireless device-specific PDCCH issuccessfully decoded, wherein the wireless device-specific PDCCH may beassociated with a new transmission, a retransmission, SPS activationand/or deactivation, or another purpose.

A wireless device may switch to a default BWP, for example, if thewireless device does not receive any control and/or data from thenetwork during the running of the BWP inactive timer. The timer may bereset, for example, upon reception of any control and/or data. The timermay be triggered, for example, if wireless device receives a DCI toswitch its active DL BWP from the default BWP to another BWP. The timermay be reset, for example, if a wireless device receives a DCI toschedule PDSCH(s) in the BWP other than the default BWP.

A DL BWP inactive timer may be defined separately from a UL BWP inactivetimer. Timers for the DL BWP and UL BWP may be set independently and/orjointly. For the separate timers (e.g., if there is DL data and UL timerexpires), UL BWP may not be deactivated since PUCCH configuration may beaffected if both DL BWP and UL BWP are activated. For the uplink, ifthere is UL feedback signal related to DL transmission, the timer may bereset. The UL timer may not be set if there is DL data. If there is ULdata and the DL timer expires, there may be no issue if the DL BWP isdeactivated since UL grant is transmitted in the default DL BWP. A BWPinactivity-timer may allow fallback to default BWP on a PCell and/orSCell.

A timer-based activation and/or deactivation of BWP may be similar to awireless device DRX timer. There may not be a separate inactivity timerfor BWP activation and/or deactivation for the wireless device DRXtimer. A wireless device DRX inactivity timer may trigger BWP activationand/or deactivation. There may be separate inactivity timers for BWPactivation and/or deactivation for the wireless device DRX timer. Forexample, the DRX timers may be defined in a MAC layer, and the BWP timermay be defined in a physical layer. A wireless device may stay in awider BWP for as long as the inactivity timer is running, for example,if the same DRX inactivity timer is used for BWP activation and/ordeactivation. The DRX inactivity timer may be set to a large value of100˜200 milliseconds for a C-DRX cycle of 320 milliseconds, which may belarger than the ON duration (e.g., 10 milliseconds). Setting the DRXinactivity timer in the above manner may provide power savings, forexample, based on a narrower BWP not being achievable. To realizewireless device power saving promised by BWP switching, a new timer maybe defined and it may be configured to be smaller than the DRXinactivity timer. From the point of view of DRX operation, BWP switchingmay allow wireless device to operate at different power levels duringthe active state, effectively providing intermediate operating pointsbetween the ON and OFF states.

With a DCI explicit activation and/or deactivation of BWP, a wirelessdevice and a base station may not be synchronized with respect to whichBWP is activated and/or deactivated. The base station scheduler may nothave CSI information related to a target BWP for channel-sensitivescheduling. The base station may be limited to conservative schedulingfor one or more first several scheduling occasions. The base station mayrely on periodic or aperiodic CSI-RS and associated CQI report(s) toperform channel-sensitive scheduling. Relying on periodic or aperiodicCSI-RS and associated CQI report(s) may delay channel-sensitivescheduling and/or lead to signaling overhead, such as if aperiodic CQIis requested (e.g., by a base station). To mitigate a delay in acquiringsynchronization and channel state information, a wireless device maytransmit an acknowledgement upon receiving an activation and/ordeactivation of a BWP. A CSI report based on the provided CSI-RSresource may be transmitted after activation of a BWP and may be used asacknowledgment of activation and/or deactivation.

A base station may provide a sounding reference signal for a target BWPafter a wireless device tunes to a new BWP. The wireless device mayreport the CSI, which may be used as an acknowledgement by the basestation to confirm that the wireless device receives an explicit DCIcommand and activates and/or deactivates the appropriate BWPs. For anexplicit activation and/or deactivation via DCI with data assignment, afirst data assignment may be carried out without a CSI for the targetBWP

A guard period may be defined to take RF retuning and related operationsinto account. A wireless device may neither transmit nor receive signalsin the guard period. A base station may need to know the length of theguard period. For example, the length of the guard period may bereported to the base station as a wireless device capability. The lengthof the guard period may be based on the numerologies of the BWPs and thelength of the slot. The length of the guard period for RF retuning maybe reported as a wireless device capability. The wireless device mayreport the guard period as an absolute time and/or in symbols.

The base station may maintain the time domain position of guard periodin alignment between the base station and the wireless device, forexample, if the base station knows the length of the guard period. Theguard period for RF retuning may be predefined for time patterntriggered BWP switching. The BWP switching and/or guard period may betriggered by DCI and/or a timer. For BWP switching following a timepattern, the position of the guard period may be defined. The guardperiod may not affect the symbols carrying CSS, for example, if thewireless device is configured to switch periodically to a default BWPfor CSS monitoring.

A single DCI may switch the wireless device's active BWP from one toanother within a given serving cell. The active BWP may be switched to asecond BWP of the same link direction, for example an UL BWP or a DLBWP. A separate field may be used in the scheduling DCI to indicate theindex of the BWP for activation such that wireless device may determinethe current DL/UL BWP according to a detected DL/UL grant withoutrequiring any other control information. The multiple scheduling DCIstransmitted in this duration may comprise the indication to the sameBWP, for example, if the BWP change does not happen during a certaintime duration. During the transit time wherein potential ambiguity mayhappen, base station may send scheduling grants in the current BWP ortogether in the other BWPs containing the same target BWP index, suchthat wireless device may obtain the target BWP index by detecting thescheduling DCI in either one of the BWPs. The duplicated scheduling DCImay be transmitted an arbitrary number (e.g., K) times. A wirelessdevice may switch to the target BWP and start to receive or transmit(UL) in the target BWP according to the BWP indication field, forexample, if the wireless device receives one of the K timestransmissions.

Switching between BWPs may introduce time gaps, for example, if wirelessdevice is unable to receive one or more messages due to re-tuning.Breaks of several time slots may severely affect the TCP ramp up as thewireless device may not be able to transmit and receive during thoseslots, affecting obtained RTT and data rate. A break in reception maymake wireless device out of reach from network point of view reducingnetwork interest to utilize short inactivity timer. If BWP switchingtakes significant time and a wireless device requires new referencesymbols to update AGC, channel estimation, etc., active BWP switchingmay not be adopted in the wireless device. In some configurations, BWPswitching may be performed where the BWP center frequency remains thesame if switching between BWPs.

A frequency location of a wireless device's RF bandwidth may beindicated by a base station. The RF bandwidth of the wireless device maybe smaller than the carrier bandwidth for considering the wirelessdevice RF bandwidth capability. The supported RF bandwidth for awireless device is usually a set of discrete values (e.g., 10 MHz, 20MHz, 50 MHz, etc.). For energy saving purpose, the wireless device RFbandwidth may be determined as the minimum available bandwidthsupporting the bandwidth of the BWP. The granularity of BWP bandwidthmay be PRB level, which may be decoupled with wireless device RFbandwidth. As a result, the wireless device RF bandwidth may be largerthan the BWP bandwidth. The wireless device may receive signals outsidethe carrier bandwidth, especially if the BWP is configured near the edgeof the carrier bandwidth. Inter-system interference or the interferencefrom an adjacent cell outside the carrier bandwidth may affect thereceiving performance of the BWP. To keep the wireless device RFbandwidth in the carrier bandwidth, the frequency location of thewireless device RF bandwidth may be indicated by the base station.

A gap duration may be determined based on a measurement duration and aretuning gap. The retuning gap may vary. If a wireless device does notneed to switch its center, the retuning may be relatively short, such as20 μs. A wireless device may indicate the necessary retuning gap for ameasurement configuration, for example, if the network may not knowwhether the wireless device needs to switch its center or not to performmeasurement. The retuning gap may depend on the current active BWP thatmay be dynamically switched via a switching mechanism. Wireless devicesmay need to indicate the retuning gap dynamically.

The measurement gap may be indirectly created, for example, if thenetwork may configure a certain measurement gap. The measurement gap maycomprise the smallest retuning latency. The smallest returning latencymay be determined, for example, if a small retuning gap may be utilizedand/or if both measurement bandwidth and active BWP is included withinthe wireless device maximum RF capability and the center frequency ofthe current active BWP may be not changed. The wireless device may skipreceiving and/or transmitting, for example, if a wireless device needsmore gap than the configured.

A different measurement gap and retuning gap may be utilized for RRM andCSI. For CSI measurement, if periodic CSI measurement outside of activeBWP may be configured, a wireless device may need to perform itsmeasurement periodically per measurement configuration. For RRM, it maybe up to wireless device implementation where to perform the measurementas long as it satisfies the measurement requirements. The worst caseretuning latency for a measurement may be used. As the retuning latencymay be different between intra-band and inter-band retuning, separatemeasurement gap configurations between intra-band and inter-bandmeasurement may be considered.

A respective DCI format may comprise an explicit identifier todistinguish them, for example, for multiple DCI formats with the sameDCI size of a same RNTI. The same DCI size may come from zero-paddingbits in at least a wireless device-specific search space.

In BWP switching, a DCI in the current BWP may need to indicate resourceallocation in the next BWP that the wireless device may be expected toswitch. The resource allocation may be based on the wirelessdevice-specific PRB indexing, which may be per BWP. A range of the PRBindices may change as the BWP changes. The DCI to be transmitted in thecurrent BWP may be based on the PRB indexing for the current BWP. TheDCI may need to indicate the RA in the new BWP, which may cause aresource conflict. To resolve the conflict without significantlyincreasing wireless devices blind detection overhead, the DCI size andbit fields may not change per BWP for a given DCI type.

As the range of the PRB indices may change as the BWP changes, one ormore employed bits among the total bit field for RA may be dependent onthe employed BWP. A wireless device may use the indicated BWP ID thatthe resource allocation may be intended to identify the resourceallocation bit field.

The DCI size of the BWP may be based on a normal DCI detection withoutBWP retuning and/or on a DCI detection during the BWP retuning A DCIformat may be independent of the BW of the active DL/UL BWP, which maybe called as fallback DCI. At least one of DCI format for DL may beconfigured to have the same size for a wireless device for one or moreconfigured DL BWPs of a serving cell. At least one of the DCI formatsfor UL may be configured to have the same size for a wireless device forone or more configured UL BWPs of a serving cell. A BWP-dependent DCIformat may be monitored at the same time (e.g. a normal DCI) for bothactive DL BWP and active UL BWP. A wireless device may monitor both DCIformats at the same time. A base station may assign the fallback DCIformat to avoid ambiguity during a transition period in the BWPactivation and/or deactivation.

If a wireless device is configured with multiple DL or UL BWPs in aserving cell, an inactive DL and/or UL BWP may be activated by a DCIscheduling a DL assignment or UL grant in the BWP. As the wirelessdevice may be monitoring the PDCCH on the currently active DL BWP, theDCI may comprise an indication to a target BWP that the wireless devicemay switch to for PDSCH reception or UL transmission. A BWP indicationmay be inserted in the wireless device-specific DCI format. The bitwidth of this field may depend on the maximum possible and/or presentlyconfigured number of DL and/or UL BWPs. The BWP indication field may bea fixed size based on the maximum number of configured BWPs.

A DCI format size may match the BW of the BWP in which the PDCCH may bereceived. To avoid an increase in the number of blind decodes, thewireless device may identify the RA field based on the scheduled BWP.For a transition from a small BWP to a larger BWP, the wireless devicemay identify the RA field as being the LSBs of the required RA field forscheduling the larger BWP.

The same DCI size for scheduling different BWPs may be defied by keepingthe same size of resource allocation fields for one or more configuredBWPs. A base station may be aware of a wireless device switching BWPsbased on a reception of ACK/NACK from the wireless device. The basestation may not be aware of a wireless device switching BWPs, forexample, if the base station does not receive at least one response fromthe wireless device. To avoid such a mismatch between base station andwireless device, a fallback mechanism may be used. The base station maytransmit the scheduling DCI for previous BWPs and for newly activatedBWP since the wireless device may receive the DCI on either BWP, forexample, if there is no response from the wireless device. The basestation may confirm the completion of the active BWP switching, forexample, after or in response to the base station receiving a responsefrom the wireless device. The base station may not transmit multipleDCIs, for example, if the same DCI size for scheduling different BWPsmay be considered and CORESET configuration may be the same fordifferent BWPs. DCI format(s) may be configured user-specifically percell rather than per BWP. The wireless device may start to monitorpre-configured search-space on the CORESET, for example, if a wirelessdevice synchronizes to a new BWP.

The size of DCI format in different BWPs may vary and may change atleast due to different size of RA bitmap on different BWPs. The size ofDCI format configured in a cell for a wireless device may be dependenton scheduled BWPs. If the DCI formats may be configured per cell, thecorresponding header size in DCI may be relatively small.

The monitored DCI format size on a search-space of a CORESET may beconfigurable with sufficiently fine granularity and/or the granularitymay be predefined. The monitored DCI format size with sufficientgranularity may be beneficial, for example, if a base station may freelyset the monitoring DCI format size on the search-spaces of a CORESET.The DCI format size may be set such that it may accommodate the largestactual DCI format size variant among one or more BWPs configured in aserving cell.

For a wireless device-specific serving cell, one or more DL BWPs and oneor more UL BWPs may be configured by a dedicated RRC for a wirelessdevice. This may be done as part of the RRC connection establishmentprocedure for a PCell. For an SCell, this may be done via RRCconfiguration indicating the SCell parameters.

A default DL and/or a default UL BWP may be activated since there may beat least one DL and/or UL BWP that may be monitored by the wirelessdevice depending on the properties of the SCell (DL only, UL only, orboth), for example, if a wireless device receives an SCell activationcommand. The BWP may be activated upon receiving an SCell activationcommand. The BWP may be informed to the wireless device via the RRCconfiguration that configured the BWP on this serving cell. For anSCell, RRC signaling for SCell configuration/reconfiguration may be usedto indicate which DL BWP and/or UL BWP may be activated if the SCellactivation command is received by the wireless device. The indicated BWPmay be the initially active DL and/or UL BWP on the SCell. The SCellactivation command may activate DL and/or UL BWP.

For an SCell, RRC signaling for the SCell configuration/reconfigurationmay be used for indicating a default DL BWP on the SCell. The default DLBWP may be used for fallback purposes. The default DL BWP may be same ordifferent from the initially activated DL and/or UL BWP indicated towireless device as part of the SCell configuration. A default UL BWP maybe configured to a wireless device for transmitting PUCCH for SR, forexample, if the PUCCH resources are not configured in every BWP for SR.

An SCell may be for DL only. For a DL only SCell, a wireless device maykeep monitoring an initial DL BWP (e.g., initial active or default)until the wireless device receives SCell deactivation command. An SCellmay be for UL only. For the UL only SCell, the wireless device maytransmit on the indicated UL BWP, for example, if a wireless devicereceives a grant. The wireless device may not maintain an active UL BWPif wireless device does not receive a grant. A failure to maintain theactive UL BWP due to a grant not being received may not deactivate theSCell. An SCell may be for UL and DL. For a UL and DL SCell, a wirelessdevice may keep monitoring an initial DL BWP (e.g., initial active ordefault) until the wireless device receives an SCell deactivationcommand. The UL BWP may be used if there may be a relevant grant or anSR transmission.

A BWP deactivation may not result in a SCell deactivation. The active DLand/or UL BWPs may be considered deactivated, for example, if thewireless device receives the SCell deactivation command.

A wireless device may be expected to perform RACH procedure on an SCellduring activation. Activation of UL BWP may be needed for the RACHprocedure. At an SCell activation, DL only (only active DL BWP) and/orDL/UL (both DL/UL active BWP) may be configured. A wireless device mayselect default UL BWP based on measurement or the network configureswhich one in its activation.

One or more BWPs may be semi-statically configured via wirelessdevice-specific RRC signaling. If a wireless device maintains RRCconnection with a primary component carrier (CC), the BWP in a secondaryCC may be configured via RRC signaling in the primary CC. One or moreBWPs may be semi-statically configured to a wireless device via RRCsignaling in a PCell. A DCI transmitted in an SCell may indicate a BWPamong the one or more configured BWP and grant detailed resource basedon the indicated BWP. For cross-CC scheduling, a DCI transmitted in aPCell may indicate a BWP among the one or more configured BWPs, andgrants detailed resource based on the indicated BWP.

A DL BWP may be initially activated for configuring CORESET formonitoring the first PDCCH in the SCell, for example, if an SCell may beactivated. The DL BWP may serve as a default DL BWP in the SCell. Forthe wireless device performing initial access via a SS block in PCell,the default DL BWP in an SCell may not be derived from SS block forinitial access. The default DL BWP in an SCell may be configured by RRCsignaling in the PCell.

An indication indicating which DL BWP and/or which UL BWP are active maybe in the RRC signaling for SCell configuration and/or reconfiguration,for example, if an SCell is activated. The RRC signaling for SCellconfiguration/reconfiguration may be used for indicating which DL BWPand/or which UL BWP are initially activated if the SCell may beactivated. An indication indicating which DL BWP and/or which UL BWP areactive may be in the SCell activation signaling, for example, if anSCell is activated. SCell activation signaling may be used forindicating which DL BWP and/or which UL BWP are initially activated ifthe SCell may be activated.

For PCells and SCells, initial default BWPs for DL and UL (e.g., forRMSI reception and PRACH transmission) may be valid until at least oneBWP is configured for the DL and UL via RRC wireless device-specificsignaling respectively. The initial default DL/UL bandwidth parts maybecome invalid and new default DL/UL bandwidth parts may take effect.The SCell configuration may comprise default DL/UL bandwidth parts.

An initial BWP on a PCell may be defined by a master information block(MIB). An initial BWP and default BWP may be separately configurable forthe SCell. An initial BWP may be the widest configured BWP of the SCell.A wireless device may retune to a default BWP that may be the narrowBWP. The SCell may be active and may be ready to be opened if anadditional data burst arrives.

A BWP on SCell may be activated by means of cross-cell scheduling DCI.The cross-cell scheduling may be configured for a wireless device. Thebase station may activate a BWP on the SCell by indicating CIF and BWPin the scheduling DCI.

A wireless device and/or base station may perform synchronizationtracking within an active DL BWP without a SS block. A trackingreference signal (TRS) and/or the DL BWP configuration may beconfigured. A DL BWP with a SS block or TRS may be configured as areference for synchronization tracking.

SS-block based RRM measurements may be decoupled within the BWPframework. Measurement configurations for each RRM and CSI feedback maybe independently configured from the BWP configurations. CSI and SRSmeasurements/transmissions may be performed within the BWP framework.

For a modulation coding scheme (MCS) assignment of the first one or moreDL data packets after active DL BWP switching, the network may assignrobust MCS to a wireless device for the first one or more DL datapackets based on RRM measurement reporting. For a MCS assignment of thefirst one or more DL data packets after active DL BWP switching, thenetwork may signal to a wireless device by active DL BWP switching DCIto trigger aperiodic CSI measurement/reporting to speed up linkadaptation convergence. For a wireless device, periodic CSI measurementoutside the active BWP in a serving cell may not supported. For awireless device, RRM measurement outside active BWP in a serving cellmay be supported. For a wireless device, RRM measurement outsideconfigured BWPs in a serving cell may be supported. RRM measurements maybe performed on a SSB and/or CSI-RS. The RRM/RLM measurements may beindependent of BWPs.

A wireless device may not be configured with aperiodic CSI reports fornon-active DL BWPs. The CSI measurement may be obtained after the BWopening and the wide-band CQI of the previous BWP may be used asstarting point for the other BWP on the component carrier.

A wireless device may perform CSI measurements for the BWP beforescheduling. Before scheduling on a new BWP, a base station may intend tofind the channel quality on the potential new BWPs before scheduling theuser on that BWP. The wireless device may switch to a different BWP andmeasure channel quality for the BWP and then transmit the CSI report.There may be no scheduling needed.

One or more scheduling request (SR) configurations may be configured fora BWP of a cell for a wireless device. A wireless device may use SRresources configured by the SR configurations in a BWP to indicate tothe base station the numerology/TTI/service type of a logical channel(LCH) or logical channel group (LCG) that triggered the SR. The maximumnumber of SR configurations may be the maximum number of logicalchannels/logical channel groups.

There may be at most one active DL BWP and at most one active UL BWP ata given time for a serving cell. A BWP of a cell may be configured witha specific numerology and/or TTI. For a logical channel and/or logicalchannel group that triggers a SR transmission while the wireless deviceoperates in one active BWP, the corresponding SR may remain triggeredbased on BWP switching.

The logical channel and/or logical channel group to SR configurationmapping may be configured and/or reconfigured based on switching of theactive BWP. The RRC dedicated signaling may configure and/or reconfigurethe logical channel and/or logical channel group to SR configurationmapping on the new active BWP if the active BWP is switched.

Mapping between the logical channel and/or logical channel group to SRconfiguration may be configured when BWP is configured. RRC maypre-configure mapping between logical channel and/or logical channelgroup to SR configurations for all the configured BWPs. In response tothe switching of the active BWP, the wireless device may employ the RRCconfigured mapping relationship for the new BWP. If BWP is configured,RRC may configure the mapping between logical channel and SRconfigurations for the BWA mapping between a logical channel and/orlogical channel group and SR configuration may be configured if a BWP isconfigured. The RRC may pre-configure mapping between logical channelsand/or logical channel groups to SR configurations for the configuredBWPs. Based on switching of the active BWP, a wireless device may usethe RRC configured mapping relationship for the new BWP. A RRC mayconfigure the mapping between logical channel and SR configurations forthe BWP. The sr-ProhibitTimer and SR_COUNTER corresponding to a SRconfiguration may continue and the value of the sr-ProhibitTimer and thevalue of the SR_COUNTER may be their values before the BWP switching.

A plurality of logical channel/logical channel group to SR configurationmappings may be configured in a serving cell. A logical channel/logicalchannel group may be mapped to at most one SR configuration per BWP. Alogical channel/logical channel group mapped onto multiple SRconfigurations in a serving cell may have one SR configuration active ata time, such as that of the active BWP. A plurality of logicalchannel/logical channel group to SR-configuration mappings may besupported in carrier aggregation (CA). A logical channel/logical channelgroup may be mapped to one (or more) SR configuration(s) in each ofPCell and PUCCH-SCell. A logical channel/logical channel groupconfigured to be mapped to one (or more) SR configuration(s) in each ofboth PCell and PUCCH-SCell may have two active SR configurations (one onPCell and one on PUCCH-SCell) at a time for CA. The SR resource isreceived first may be used.

A base station may configure one SR resource per BWP for the samelogical channel/logical channel group. If a SR for one logicalchannel/logical channel group is pending, a wireless device may transmita SR with the SR configuration in another BWP after BWP switching. Thesr-ProhibitTimer and SR_COUNTER for the SR corresponding to the logicalchannel/logical channel group may continue based on BWP switching. Thewireless device may transmit the SR in another SR configurationcorresponding to the logical channel/logical channel group in anotherBWP after BWP switching if a SR for one logical channel/logical channelgroup may be pending.

If multiple SRs for logical channels/logical channel groups mapped todifferent SR configurations are triggered, the wireless device maytransmit one SR corresponding to the highest priority logicalchannel/logical channel group. The wireless device may transmit multipleSRs with different SR configurations. SRs triggered at the same time(e.g., in the same NR-UNIT) by different logical channels/logicalchannel groups mapped to different SR configurations may be merged intoa single SR corresponding to the SR triggered by the highest prioritylogical channel/logical channel group.

If an SR of a first SR configuration is triggered by a first logicalchannel/logical channel group while an SR procedure triggered by a lowerpriority logical channel/logical channel group may be on-going onanother SR configuration, the later SR may be allowed to trigger anotherSR procedure on its own SR configuration independently of the other SRprocedure. A wireless device may be allowed to send independentlytriggered SRs for logical channels/logical channel groups mapped todifferent SR configurations. A wireless device may be allowed to sendtriggered SRs for LCHs corresponding to different SR configurationsindependently.

The dsr-TransMax may be independently configured per SR configuration.The SR_COUNTER may be maintained for each SR configurationindependently. A common SR_COUNTER may be maintained for all the SRconfigurations per BWP.

PUCCH resources may be configured per BWP. The PUCCH resources in thecurrently active BWP may be used for UCI transmission. PUCCH resourcesmay be configured per BWP. PUCCH resources may be utilized in a BWP notcurrently active for UCI transmission. PUCCH resources may be configuredin a default BWP and BWP switching may be necessary for PUCCHtransmission. A wireless device may be allowed to send SR1 in BWP1 eventhough BWP1 may be no longer active. The network may reconfigure (e.g.,pre-configure) the SR resources so that both SR1 and SR2 may besupported in the active BWP. An anchor BWP may be used for SRconfiguration. The wireless device may send SR2 as a fallback.

A logical channel/logical channel group mapped to a SR configuration inan active BWP may also be mapped to the SR configuration in another BWPto imply same or different information, such as numerology and/or TTIand priority. A MAC entity can be configured with a plurality of SRconfigurations within the same BWP. The plurality of the SRconfigurations may be on the same BWP, on different BWPs, or ondifferent carriers. The numerology of the SR transmission may differfrom the numerology that the logical channel/logical channel group thattriggered the SR may be mapped to.

The PUCCH resources for transmission of the SR may be on different BWPsor different carriers for a LCH mapped to multiple SR configurations.The selection of which configured SR configuration within the active BWPto transmit one SR may be up to wireless device implementation ifmultiple SRs are triggered. A single BWP can support multiple SRconfigurations. Multiple sr-ProhibitTimers (e.g., each for one SRconfiguration) may be running at the same time. A drs-TransMax may beindependently configured per SR configuration. A SR_COUNTER may bemaintained for each SR configuration independently. A single logicalchannel/logical channel group may be mapped to zero or one SRconfigurations. A PUCCH resource configuration may be associated with aUL BWP. One or more logical channels may be mapped to none or one SRconfiguration per BWP in CA.

A BWP may consist of a group of contiguous PRBs in the frequency domain.The parameters for each BWP configuration may include numerology,frequency location, bandwidth size (e.g., in terms of PRBs), CORESET.CORESET may be required for each BWP configuration, such as for a singleactive DL bandwidth part for a given time instant. One or more BWPs maybe configured for each component carrier, for example, if the wirelessdevice is in RRC connected mode.

The configured downlink assignment may be initialized (e.g., if notactive) or re-initialized (e.g., if already active) using PDCCH if a newBWP may be activated. For uplink SPS, the wireless device may have toinitialize and/or re-initialize the configured uplink grant if switchingfrom one BWP to anther BWP. If a new BWP is activated, the configureduplink grant may be initialized (e.g., if not already active) orre-initialized (e.g., if already active) using PDCCH.

For type 1 uplink data transmission without grant, there may be no L1signaling to initialize or re-initialize the configured grant. Thewireless device may not determine that the type 1 configured uplinkgrant may be active if the BWP may be switched, for example, even if thewireless device is already active in the previous BWP. The type 1configured uplink grant may be re-configured using RRC dedicatedsignaling for switching the BWP. The type 1 configured uplink grant maybe re-configured using dedicated RRC signaling if a new BWP isactivated.

If SPS is configured on the resources of a BWP and the BWP issubsequently deactivated, the SPS grants or assignments may notcontinue. All configured downlink assignments and configured uplinkgrants using resources of this BWP may be cleared, for example, if a BWPis deactivated. The MAC entity may clear the configured downlinkassignment or/and uplink grants after receiving activation and/ordeactivation of BWP.

The units of drx-RetransmissionTimer and drx-ULRetransmissionTimer maybe OFDM symbol corresponding to the numerology of the active BWP. If awireless device is monitoring an active DL BWP for a long time withoutactivity, the wireless device may move to a default BWP in order to savepower. A BWP inactivity timer may be introduced to switch from an activeBWP to the default BWP. Autonomous switching to a DL default BWP mayconsider both DL BWP inactivity timers and/or DRX timers, such as HARQRTT and DRX retransmission timers. A DL BWP inactivity timer may beconfigured per MAC entity. A wireless device may be configured tomonitor PDCCH in a default BWP, for example, if a wireless device uses along DRX cycle.

A power headroom report (PHR) may not be triggered due to the switchingof BWP. The support of multiple numerologies/BWPs may not impact PHRtriggers. A PHR may be triggered upon BWP activation. A prohibit timermay start upon PHR triggering due to BWP switching. A PHR may not betriggered due to BWP switching while the prohibit timer may be running APHR may be reported per activated and/or deactivated BWP.

Packet Data Convergence Protocol (PDCP) duplication may be in anactivated state while the wireless device receives the BWP deactivationcommand. The PDCP duplication may not be deactivated, for example, ifthe BWP on which the PDCP duplication is operated on is deactivated. ThePDCP entity may stop sending the data to the deactivated RLC buffer, forexample, even if the PDCP duplication may not be deactivated.

RRC signaling may configure a BWP to be activated, for example, if theSCell is activated. Activation and/or deactivation MAC CE may be used toactivate both the SCell and the configured BWP. A HARQ entity can servedifferent BWP within one carrier.

For a wireless device-specific serving cell, one or more DL BWPs and oneor more UL BWPs may be configured by dedicated RRC for a wirelessdevice. A single scheduling DCI may switch the wireless device's activeBWP from one to another. An active DL BWP may be deactivated by means oftimer for a wireless device to switch its active DL bandwidth part to adefault DL bandwidth part. A narrower BWP may be used for DL controlmonitoring and a wider BWP may be used for scheduled data. Small datamay be allowed in the narrower BWP without triggering BWP switching.

A base station may transmit a plurality of beams to a wireless device. Aserving beam may be determined, from the plurality of beams, for thewireless communications between the base station and the wirelessdevice. One or more candidate beams may also be determined, from theplurality of beams, for providing the wireless communications if a beamfailure (e.g., any wireless or communication resource failure) eventoccurs, for example, such that the serving beam becomes unable toprovide the desired communications. One or more candidate beams may bedetermined by a wireless device and/or by a base station. By determiningand configuring a candidate beam, the wireless device and base stationmay continue wireless communications if the serving beam experiences abeam failure event.

Single beam and multi-beam operations may be supported, for example, ina NR (New Radio) system. In a multi-beam example, a base station (e.g.,gNB) may perform a downlink beam sweep to provide coverage for downlinkSynchronization Signals (SSs) and common control channels. Wirelessdevices may perform uplink beam sweeps to access a cell. For a singlebeam, a base station may configure time-repetition transmission withinone SS block. This time-repetition may comprise, for example, one ormore of a primary synchronization signal (PSS), a secondarysynchronization signal (SSS), or a physical broadcast channel (PBCH).These signals may be in a wide beam. In a multi-beam example, a basestation may configure one or more of these signals and physicalchannels, such as in an SS block, in multiple beams. A wireless devicemay identify, for example, from an SS block, an OFDM symbol index, aslot index in a radio frame, and a radio frame number from an SS block.

In an RRC_INACTIVE state or in an RRC_IDLE state, a wireless device mayassume that SS blocks form an SS burst and an SS burst set. An SS burstset may have a given periodicity. SS blocks may be transmitted togetherin multiple beams (e.g., in multiple beam examples) to form an SS burst.One or more SS blocks may be transmitted via one beam. If multiple SSbursts are transmitted with multiple beams, these SS bursts together mayform an SS burst set, such as shown in FIG. 15. A base station 1501(e.g., a gNB in NR) may transmit SS bursts 1502A to 1502H during timeperiods 1503. A plurality of these SS bursts may comprise an SS burstset, such as an SS burst set 1504 (e.g., SS bursts 1502A and 1502E). AnSS burst set may comprise any number of a plurality of SS bursts 1502Ato 1502H. Each SS burst within an SS burst set may transmitted at afixed or variable periodicity during time periods 1503.

A wireless device may detect one or more of PSS, SSS, or PBCH signalsfor cell selection, cell reselection, and/or initial access procedures.The PBCH or a physical downlink shared channel (PDSCH) scheduling systeminformation may be broadcasted by a base station to multiple wirelessdevices. The PDSCH may be indicated by a physical downlink controlchannel (PDCCH) in a common search space. The system information maycomprise system information block type 2 (SIB2). SIB2 may carry one ormore physical random access channel (PRACH) configurations. A basestation (e.g., a gNB in NR) may have one or more RACH configurationswhich may include a PRACH preamble pool, time and/or frequency radioresources, and other power related parameters. A wireless device mayselect a PRACH preamble from a RACH configuration to initiate acontention-based RACH procedure or a contention-free RACH procedure. Awireless device may perform a 4-step RACH procedure, which may be acontention-based RACH procedure or a contention-free RACH procedure.

FIG. 16 shows examples of (a) a contention-based four-step RA procedure,(b) a contention free three-step RA procedure, (c) descriptions of acontention-based four-step RA procedure, and (d) a contention freetwo-step RA procedure. A four-step RA procedure may comprise a RAPtransmission in a first step, an RAR transmission in a second step, ascheduled transmission of one or more transport blocks (TBs) in a thirdstep, and contention resolution in a fourth step.

In step 1601, a base station may transmit four-step RA configurationparameters to a wireless device (e.g., a UE). The base station maygenerate and transmit RA configuration parameters periodically, e.g.,based on a timer. The base station may broadcast RA configurationparameters in one or more messages. The wireless device may perform aRAP selection process at step 1602, e.g., after receiving the four-stepRA configuration parameters. In a contention-based RA procedure, such asshown in part (a) of FIG. 16, the RA configuration parameters maycomprise a root sequence that may be used by the wireless device togenerate a RAP. The RAP may be randomly selected by the wireless device,among various RAP candidates generated by the root sequence, during theRAP selection process. The wireless device may perform the RAP selectionusing one or more RAP selections procedures, such as described herein.

In a first step of the RA procedure, at step 1603, a wireless device maytransmit a RAP, e.g., using a configured RA preamble format with atransmission (Tx) beam. A random access channel (RACH) resource may bedefined as a time-frequency resource to transmit a RAP. Broadcast systeminformation may indicate whether wireless device should transmit onepreamble, or multiple or repeated preambles, within a subset of RACHresources.

A base station may configure an association between a downlink (DL)signal and/or channel, and a subset of RACH resources and/or a subset ofRAP indices, for determining the DL transmission in the second step.Based on the DL measurement and the corresponding association, awireless device may select the subset of RACH resources and/or thesubset of RAP indices. Two RAP groups may be informed by broadcastsystem information and one may be optional. If a base station configuresthe two groups in the four-step RA procedure, a wireless device may usedetermine which group from which the wireless device selects an RAP, forexample, based on the pathloss and/or a size of the message to betransmitted by the wireless device in the third step. A base station mayuse a group type to which a RAP belongs as an indication of the messagesize in the third step and the radio conditions at a wireless device. Abase station may broadcast the RAP grouping information along with oneor more thresholds on system information.

In the second step of the four-step RA procedure, at step 1604, a basestation may transmit a random access response (RAR) to the wirelessdevice. The base station may transmit the RAR in response to an RAP thatthe wireless device may transmit. A wireless device may monitor thePDCCH carrying a DCI, to detect RARs transmitted on a PDSCH in an RAresponse window. The DCI may be CRC-scrambled by the RA-RNTI (RandomAccess-Radio Network Temporary Identifier). The RA-RNTI may be used onthe PDCCH if Random Access Response messages are transmitted. TheRA-RNTI may unambiguously identify which time-frequency resource is usedby the MAC entity to transmit the Random Access preamble. The RAresponse window may start at a subframe that contains the end of an RAPtransmission, plus three subframes. The RA response window may have thelength indicated by ra-ResponseWindowSize. A wireless device maydetermine the RA-RNTI associated with the PRACH in which the wirelessdevice transmits an RAP by the following operation:RA-RNTI=1+t_id+10*f_idwhere t_id is the index of the first subframe of the specified PRACH(0≤t_id<10), and f_id is the index of the specified PRACH within thatsubframe, in ascending order of frequency domain (0≤f_id<6). Differenttypes of wireless devices, e.g., narrow band-Internet of Things(NB-IoT), bandwidth limited (BL)-UE, and/or UE-Extended Coverage(UE-EC), may use different formulas or operations for determiningRA-RNTI. A base station may configure an association between a DL signalor channel, a subset of RACH resources, and/or a subset of RAP indexes.Such an association may be for determining the DL transmission in thesecond step of the RA procedure, at step 1604 of FIG. 16. Based on theDL measurement and the corresponding association, a wireless device mayselect the subset of RACH resources and/or the subset of RAP indices.FIG. 18 shows contents of a MAC RAR. For example, FIG. 18A shows thecontents of a MAC RAR of a wireless device, FIG. 18B shows the contentsof a MAC RAR of a MTC wireless device, and FIG. 18C shows the contentsof MAC RAR of a NB-IOT wireless device.

In the third step of the four-step RA procedure (e.g., step 1605 in FIG.16), a wireless device may adjust an UL time alignment by using the TAvalue corresponding to the TA command in the received RAR in the secondstep (e.g., step 1604 in FIG. 16). A wireless device may transmit one ormore TBs to a base station using the UL resources assigned in the ULgrant in the received RAR. One or more TBs that a wireless device maytransmit in the third step (e.g., step 1605 in FIG. 16) may comprise RRCsignaling, such as an RRC connection request, an RRC connectionRe-establishment request, or an RRC connection resume request. The oneor more TBs may also comprise a wireless device identity, e.g., whichmay be used as part of the contention-resolution mechanism in the fourthstep (e.g., step 1606 in FIG. 16).

The fourth step in the four-step RA procedure (e.g., step 1606 in FIG.16) may comprise a DL message for contention resolution. Based on thesecond step (e.g., step 1604 in FIG. 16), one or more wireless devicesmay perform simultaneous RA attempts selecting the same RAP in the firststep (e.g., step 1603 in FIG. 16), and/or receive the same RAR with thesame TC-RNTI in the second step (e.g., step 1604 in FIG. 16). Thecontention resolution in the fourth step may be to ensure that awireless device does not incorrectly use another wireless deviceidentity. The contention resolution mechanism may be based on either aC-RNTI on a PDCCH, or a wireless device Contention Resolution Identityon a DL-SCH, e.g., depending on whether or not a wireless device has aC-RNTI. If a wireless device has a C-RNTI, e.g., if the wireless devicedetects the C-RNTI on the PDCCH, the wireless device may determine thesuccess of RA procedure. If the wireless device does not have a C-RNTI(e.g., if a C-RNTI is not pre-assigned), the wireless device may monitora DL-SCH associated with a TC-RNTI, e.g., that a base station maytransmit in an RAR of the second step. In the fourth step (e.g., step1606 in FIG. 16), the wireless device may compare the identity in thedata transmitted by the base station on the DL-SCH with the identitythat the wireless device transmits in the third step (e.g., step 1605 inFIG. 16). If the wireless determines that two identities are the same orsatisfy a threshold similarity, the wireless device may determine thatthe RA procedure is successful. If the wireless device determines thatthe RA is successful, the wireless device may promote the TC-RNTI to theC-RNTI. A TC-RNTI may be an identifier initially assigned to a wirelessdevice when the wireless device first attempts to access a base station.A TC-RNTI may be used for a wireless device in an idle state. Afteraccess is allowed by the base station, a C-RNTI may be used forindicating the wireless device. A C-RNTI may be used for a wirelessdevice in an inactive or an active state.

The fourth step in the four-step RA procedure (e.g., step 1606 in FIG.16) may allow HARQ retransmission. A wireless device may start amac-ContentionResolutionTimer when the wireless device transmits one ormore TBs to a base station in the third step (e.g., step 1605 in FIG.16). The wireless may restart the mac-ContentionResolutionTimer at eachHARQ retransmission. When a wireless device receives data on the DLresources identified by C-RNTI or TC-RNTI in the fourth step (e.g., step1606 in FIG. 16), the wireless device may stop themac-ContentionResolutionTimer. If the wireless device does not detectthe contention resolution identity that matches the identity transmittedby the wireless device in the third step (e.g., step 1605 in FIG. 16),the wireless device may determine that the RA procedure has failed andthe wireless device may discard the TC-RNTI. Additionally oralternatively, if the mac-ContentionResolutionTimer expires, thewireless device may determine that the RA procedure has failed and thewireless device may discard the TC-RNTI. If the wireless devicedetermines that the contention resolution has failed, the wirelessdevice may flush the HARQ buffer used for transmission of the MAC PDUand the wireless device may restart the four-step RA procedure from thefirst step (e.g., step 1603 in FIG. 16). The wireless device may delaysubsequent RAP transmission, e.g., by a backoff time. The backoff timemay be randomly selected, e.g., according to a uniform distributionbetween 0 and the backoff parameter value corresponding to the BI in theMAC PDU for RAR.

In a four-step RA procedure, the usage of the first two steps may be,for example, to obtain an UL time alignment for a wireless device and/orto obtain an uplink grant. The third and fourth steps may be used tosetup RRC connections, and/or resolve contention from different wirelessdevices.

Part (b) of FIG. 16 shows a three-step contention free RA procedure. Abase station may transmit RA configuration parameters to a wirelessdevice (e.g., a UE), in step 1610. In a contention-free RA procedure,such as shown in part (b) of FIG. 16, the configuration parameters mayindicate to the wireless device what preamble to send to the basestation and when to send the preamble. The base station may alsotransmit a control command to the wireless device at step 1611. Thecontrol command may comprise, e.g., downlink control information. In afirst step of the RA procedure, the wireless device may transmit arandom access preamble transmission to the base station at step 1612.The RAP transmission may be based on the RA configuration parameters andthe control command. In a second step of the RA procedure, the basestation may transmit to the wireless device a random access response atstep 1613. In a third step of the RA procedure, the wireless device maytransmit scheduled transmissions at step 1614. The scheduledtransmissions may be based on the RAR. The contention free RA proceduremay end with the third step. Thereafter, the base station may transmit adownlink transmission to the wireless device at step 1615. This downlinktransmission may comprise, e.g., an acknowledgement (ACK) indication, anon-acknowledgement (NACK) indication, data, or other information.Contention-free RA procedures such as described above may have reducedlatency compared with contention-based RA procedures. Contention-basedRA procedures may involve collisions, such as when more than onewireless device is attempting to communicate with the same base stationat the same time.

Part (c) of FIG. 16 shows an example of common language descriptionsthat may facilitate an understanding of some of the messaging involvedin the contention-based four-step RA procedure described above regardingpart (a) of FIG. 16. In step 1 of the RA procedure, a wireless devicemay send a communication to a base station similar to a request such as,“Hello, can I camp on?” (step 1620). If the base station can accommodatethe wireless device request, the base station may respond to thewireless device with a message similar to an instruction such as “Sendyour info & data here” (step 1621). Based on the base station'sresponse, the wireless device may send a message similar to a responsesuch as “Here you are” (step 1622). Based on the information received bythe base station, the base station may respond with a message similar toa grant such as “You are now in” (step 1623).

Part (d) of FIG. 16 shows an example of a two-step contention freerandom access procedure of a wireless device. At step 1630, the wirelessdevice may receive RA configuration parameters from a base station(e.g., from a handover source base station, and/or from a handovertarget base station via the handover source base station). The RAconfiguration parameters may comprise one or more parameters indicatinga type of a random access process. The type of the random access processmay indicate a two-step random access process. At step 1631, thewireless device may transmit an RA preamble and one or more transportblocks as a first step of the procedure, e.g., overlapping in time witheach other. In response to the RA preamble and/or the one or moretransport blocks, at step 1632, the wireless device may receive an RAresponse from a base station (e.g., a handover target base station).

FIG. 17 shows an example of a MAC PDU comprising a MAC header and MACRARs. A four-step RA procedure may use the arrangement shown in FIG. 17.A two-step RA procedure may also use the arrangement shown in FIG. 17.Additionally or alternatively, a two-step RA procedure may use avariation of the arrangement shown in FIG. 17, e.g., with additional orfewer fields, and/or with longer or shorter fields. If an RAR comprisesa RAPID corresponding to a RAP that a wireless device transmits, thewireless device may process the data in the RAR. The data in the RAR maycomprise, e.g., one or more of a timing advance (TA) command, a ULgrant, and/or a Temporary C-RNTI (TC-RNTI). The MAC header may comprisesubheaders, such as an E/T/R/R/BI subheader (described further below)and up to n number of E/T/RAPID subheaders (described further below).The E/T/R/R/BI subheader may comprise an octet of bits comprising 1 biteach of E, T, R, and R, and four bits of BI. Each of n E/T/RAPIDsubheaders may comprise an octet comprising 1 bit each of E and T, and 6bits of an RAPID. The E/T/R/R/BI subheader may comprise a MAC SubPDU(e.g., MAC SubPDU 1 or MAC SubPDU 2). The MAC SubPDU may be for a BI, aRAPID, and/or an RAR.

PSS, SSS, and/or PBCH may be repeated, for example, for multiple beamsfor a cell, to support cell selection, reselection, and/or initialaccess procedures. A RACH process is shown in FIG. 19. For an SS burst,the associated PBCH, or a PDSCH (e.g., indicated by a PPDCCH in commonsearch space), scheduling system information (e.g., a SIB2), may bebroadcasted to multiple wireless devices. The system information (e.g.,a SIB2) may carry a PRACH configuration for a beam. A base station mayhave a RACH configuration for a beam, which may include PRACH preamblepool, time and/or frequency radio resources, and/or other power relatedparameters.

A wireless device may use a PRACH preamble selected from a RACHconfiguration to initiate a contention-based RACH procedure or acontention-free RACH procedure. The wireless device may perform a 4-stepRACH procedure, which may be a contention-based or contention-free RACHprocedure. The wireless device may select a beam associated with an SSblock that may have the best receiving signal quality. The wirelessdevice may successfully detect a cell identifier that may be associatedwith the cell and decode system information with a RACH configuration.The wireless device may use one PRACH preamble and select one PRACHresource from RACH resources indicated by the system informationassociated with the selected beam. A PRACH resource may comprise atleast one of: a PRACH index indicating a PRACH preamble, a PRACH format,a PRACH numerology, time and/or frequency radio resource allocation,power setting of a PRACH transmission, and/or other radio resourceparameters. For a contention-free RACH procedure, the PRACH preamble andresource may be indicated in a DCI or other high layer signaling.

FIG. 19 shows an example of a random access procedure (e.g., via a RACH)that may include sending, by a base station, one or more SS blocks. Awireless device 1920 (e.g., a UE) may transmit one or more preambles toa base station 1921 (e.g., a gNB in NR). Each preamble transmission bythe wireless device may be associated with a separate random accessprocedure, such as shown in FIG. 19. The random access procedure maybegin at step 1901 with a base station 1921 (e.g., a gNB in NR) sendinga first SS block to a wireless device 1921 (e.g., a UE). Any of the SSblocks may comprise one or more of a PSS, SSS, tertiary synchronizationsignal (TSS), or PBCH signal. The first SS block in step 1901 may beassociated with a first PRACH configuration. At step 1902, the basestation 1921 may send to the wireless device 1920 a second SS block thatmay be associated with a second PRACH configuration. At step 1903, thebase station 1921 may send to the wireless device 1920 a third SS blockthat may be associated with a third PRACH configuration. At step 1904,the base station 1921 may send to the wireless device 1920 a fourth SSblock that may be associated with a fourth PRACH configuration. Anynumber of SS blocks may be sent in the same manner in addition to, orreplacing, steps 1903 and 1904. An SS burst may comprise any number ofSS blocks. For example, SS burst 1910 comprises the three SS blocks sentduring steps 1902-1904.

The wireless device 1920 may send to the base station 1921 a preamble,at step 1905, for example, after or in response to receiving one or moreSS blocks or SS bursts. The preamble may comprise a PRACH preamble, andmay be referred to as RA Msg 1. The PRACH preamble may be transmitted instep 1905 according to or based on a PRACH configuration that may bereceived in an SS block (e.g., one of the SS blocks from steps1901-1904) that may be determined to be the best SS block beam. Thewireless device 1920 may determine a best SS block beam from among SSblocks it may receive prior to sending the PRACH preamble. The basestation 1921 may send a random access response (RAR), which may bereferred to as RA Msg2, at step 1906, for example, after or in responseto receiving the PRACH preamble. The RAR may be transmitted in step 1906via a DL beam that corresponds to the SS block beam associated with thePRACH configuration. The base station 1921 may determine the best SSblock beam from among SS blocks it previously sent prior to receivingthe PRACH preamble. The base station 1921 may receive the PRACH preambleaccording to or based on the PRACH configuration associated with thebest SS block beam.

The wireless device 1920 may send to the base station 1921 anRRCConnectionRequest and/or RRCConnectionResumeRequest message, whichmay be referred to as RA Msg3, at step 1907, for example, after or inresponse to receiving the RAR. The base station 1921 may send to thewireless device 1920 an RRCConnectionSetup and/or RRCConnectionResumemessage, which may be referred to as RA Msg4, at step 1908, for example,after or in response to receiving the RRCConnectionRequest and/orRRCConnectionResumeRequest message. The wireless device 1920 may send tothe base station 1921 an RRCConnectionSetupComplete and/orRRCConnectionResumeComplete message, which may be referred to as RAMsg5, at step 1909, for example, after or in response to receiving theRRCConnectionSetup and/or RRCConnectionResume. An RRC connection may beestablished between the wireless device 1920 and the base station 1921,and the random access procedure may end, for example, after or inresponse to receiving the RRCConnectionSetupComplete and/orRRCConnectionResumeComplete message.

A best beam, including but not limited to a best SS block beam, may bedetermined based on a channel state information reference signal(CSI-RS). A wireless device may use a CSI-RS in a multi-beam system forestimating the beam quality of the links between the wireless device anda base station. For example, based on a measurement of a CSI-RS, awireless device may report CSI for downlink channel adaption. A CSIparameter may include a precoding matrix index (PMI), a channel qualityindex (CQI) value, and/or a rank indicator (RI). A wireless device mayreport a beam index based on a reference signal received power (RSRP)measurement on a CSI-RS. The wireless device may report the beam indexin a CSI resource indication (CRI) for downlink beam selection, andassociated with the RSRP value of the beam. A base station may transmita CSI-RS via a CSI-RS resource, such as via one or more antenna ports,or via one or more time and/or frequency radio resources. A beam may beassociated with a CSI-RS. A CSI-RS may comprise an indication of a beamdirection. Each of a plurality of beams may be associated with one of aplurality of CSI-RSs. A CSI-RS resource may be configured in acell-specific way, for example, via common RRC signaling. Additionallyor alternatively, a CSI-RS resource may be configured in a wirelessdevice-specific way, for example, via dedicated RRC signaling and/orlayer 1 and/or layer 2 (L1/L2) signaling. Multiple wireless devices inor served by a cell may measure a cell-specific CSI-RS resource. Adedicated subset of wireless devices in or served by a cell may measurea wireless device-specific CSI-RS resource. A base station may transmita CSI-RS resource periodically, using aperiodic transmission, or using amulti-shot or semi-persistent transmission. In a periodic transmission,a base station may transmit the configured CSI-RS resource using aconfigured periodicity in the time domain. In an aperiodic transmission,a base station may transmit the configured CSI-RS resource in adedicated time slot. In a multi-shot or semi-persistent (SP)transmission, a base station may transmit the configured CSI-RS resourcewithin a configured period. A base station may transmit one or more SPCSI-RS with a configured periodicity, with a limited or unlimitedduration. A base station may configure different CSI-RS resources indifferent terms for different purposes. Different terms may include, forexample, cell-specific, device-specific, periodic, aperiodic,multi-shot, or other terms. Different purposes may include, for example,beam management, CQI reporting, or other purposes.

FIG. 20 shows an example of transmitting CSI-RSs periodically for abeam. A base station 20701 may transmit a beam in a predefined order inthe time domain, such as during time periods 2003. Beams used for aCSI-RS transmission, such as for CSI-RS 2004 in transmissions 2002Cand/or 2003E, may have a different beam width relative to a beam widthfor SS-blocks transmission, such as for SS blocks 2002A, 2002B, 2002D,and 2002F-2002H. Additionally or alternatively, a beam width of a beamused for a CSI-RS transmission may have the same value as a beam widthfor an SS block. Some or all of one or more CSI-RSs may be included inone or more beams. An SS block may occupy a number of OFDM symbols(e.g., 4), and a number of subcarriers (e.g., 240), carrying asynchronization sequence signal. The synchronization sequence signal mayidentify a cell.

FIG. 21 part “A” shows an example of an activation/deactivation CSI-RSresources MAC control element. The activation/deactivation CSI-RSresources MAC control element may be identified by a MAC subheader withLCID. The activation/deactivation CSI-RS resources MAC control elementmay have a variable size that may be based on the number of CSIprocesses configured with csi-RS-NZP-Activation by RRC (N). The N numberof octets, shown in FIG. 21 part “A,” each of which may comprise anumber of A fields (e.g., A1 to Ai, described below), may be included inascending order of a CSI process ID, such as the CSI-ProcessId.

FIG. 21 part “B” shows an example of an activation/deactivation CSI-RScommand that may activate and/or deactivate CSI-RS resources for a CSIprocess. For example, for a wireless device that is configured withtransmission mode 9, N equals 1. Transmission mode 9 may be atransmission mode in which a base station may transmit data packets withup to 8 layers, for example, if configured with multiple antennas. Awireless device may receive the data packets based on multiple DMRSs(e.g., up to 8 DMRSs (or DMRS ports)). The activation/deactivationCSI-RS resources MAC control element may apply to the serving cell onwhich the wireless device may receive the activation/deactivation ofCSI-RS resources MAC control element.

Activation/deactivation CSI-RS resources MAC control elements maycomprise an octet of fields, shown as fields A1 to A8, that may indicatethe activation/deactivation status of the CSI-RS resources configured byupper layers for the CSI process. A1 may correspond to the first entryin a list of CSI-RS, which may be specified by csi-RS-ConfigNZP-ApListconfigured by upper layers. A2 may correspond to the second entry in thelist of CSI-RS, and each of A3 through A8 may correspond to the thirdthrough eighth entry, respectively, in the list of CSI-RS. The Ai fieldmay be set to “1” to indicate that the i^(th) entry in the list ofCSI-RS, which may be specified by csi-RS-ConfigNZP-ApList, shall beactivated. The Ai field may be set to “0” to indicate that the i^(th)entry in the list shall be deactivated. For each CSI process, the numberof Ai fields (e.g., i=1, 2, . . . , 8) which are set to “1” may be equalto the value of a higher-layer parameter, such as activatedResources.

A wireless device may be triggered with aperiodic CSI reporting, forexample, after receiving a RRC for CSI-RS configuration and a MAC layersignaling for CSI-RS activation. The aperiodic CSI reporting may beassociated with the CSI-RS resources indicated in a DCI, for example,with DCI format 0C. A CSI request field in DCI format 0C may indicatefor which CSI process and/or CSI-RS resource the CSI reporting isconfigured, such as shown in FIG. 22.

As shown in FIG. 23, a CSI-RS may be mapped in time and frequencydomains. Each square shown in FIG. 23 may represent a resource blockwithin a bandwidth of a cell. Each resource block may comprise a numberof subcarriers. A cell may have a bandwidth comprising a number ofresource blocks. A base station (e.g., a gNB in NR) may transmit one ormore Radio Resource Control (RRC) messages comprising CSI-RS resourceconfiguration parameters for one or more CSI-RS. One or more of thefollowing parameters may be configured by higher layer signaling foreach CSI-RS resource configuration: CSI-RS resource configurationidentity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol andRE locations in a subframe), CSI-RS subframe configuration (e.g.,subframe location, offset, and periodicity in a radio frame), CSI-RSpower parameter, CSI-RS sequence parameter, CDM type parameter,frequency density, transmission comb, QCL parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

CSI-RS may be configured using common parameters, for example, when aplurality of wireless devices receive the same CSI-RS signal. CSI-RS maybe configured using wireless device dedicated parameters, for example,when a CSI-RS is configured for a specific wireless device. CSI-RSs maybe included in RRC signaling. A wireless device may be configured, forexample, depending on different MIMO beamforming types (e.g., CLASS A orCLASS B), with one or more CSI-RS resource configurations per CSIprocess. A wireless device may be configured using at least RRCsignaling.

FIG. 23 shows three beams that may be configured for a wireless device,for example, in a wireless device-specific configuration. Any number ofadditional beams (e.g., represented by the column of blank squares) orfewer beams may be included. Beam 1 may be allocated with CSI-RS 1 thatmay be transmitted in some subcarriers in a resource block (RB) of afirst symbol. Beam 2 may be allocated with CSI-RS 2 that may betransmitted in some subcarriers in a RB of a second symbol. Beam 3 maybe allocated with CSI-RS 3 that may be transmitted in some subcarriersin a RB of a third symbol. All subcarriers in a RB may not necessarilybe used for transmitting a particular CSI-RS (e.g., CSI-RS1) on anassociated beam (e.g., beam 1) for that CSI-RS. By using frequencydivision multiplexing (FDM), other subcarriers, not used for beam 1 forthe wireless device in the same RB, may be used for other CSI-RStransmissions associated with a different beam for other wirelessdevices. Additionally or alternatively, by using time domainmultiplexing (TDM), beams used for a wireless device may be configuredsuch that different beams (e.g., beam 1, beam 2, and beam 3) for thewireless device may be transmitted using some symbols different frombeams of other wireless devices.

A wireless device may perform downlink beam management using a wirelessdevice-specific configured CSI-RS. In a beam management procedure, awireless device may monitor a channel quality of a beam pair link. Thebeam pair link may comprise a transmitting beam from a base station(e.g., a gNB in NR) and a receiving beam by the wireless device (e.g., aUE). If multiple CSI-RSs associated with multiple beams are configured,a wireless device may monitor multiple beam pair links between the basestation and the wireless device.

A wireless device may transmit one or more beam management reports to abase station. A beam management report may indicate one or more beampair quality parameters, comprising, for example, one or more beamidentifications, RSRP, PMI, CQI, and/or RI, of a subset of configuredbeams.

A base station and/or a wireless device may perform a downlink L1/L2beam management procedure. One or more downlink L1/L2 beam managementprocedures may be performed within one or multiple transmission andreceiving points (TRPs) FIG. 24 shows examples of three beam managementprocedures, P1, P2, and P3. Procedure P1 may be used to enable awireless device measurement on different transmit (Tx) beams of a TRP(or multiple TRPs), for example, to support a selection of Tx beamsand/or wireless device receive (Rx) beam(s) (shown as shaded ovals inthe top row and bottom row, respectively, of P1). Beamforming at a TRP(or multiple TRPs) may include, for example, an intra-TRP and/orinter-TRP Tx beam sweep from a set of different beams (shown, in the toprows of P1 and P2, as unshaded ovals rotated in a counter-clockwisedirection indicated by the dashed arrow). Beamforming at a wirelessdevice 2401, may include, for example, a wireless device Rx beam sweepfrom a set of different beams (shown, in the bottom rows of P1 and P3,as unshaded ovals rotated in a clockwise direction indicated by thedashed arrow). Procedure P2 may be used to enable a wireless devicemeasurement on different Tx beams of a TRP (or multiple TRPs) (shown, inthe top row of P2, as unshaded ovals rotated in a counter-clockwisedirection indicated by the dashed arrow), for example, which may changeinter-TRP and/or intra-TRP Tx beam(s). Procedure P2 may be performed,for example, on a smaller set of beams for beam refinement than inprocedure P1. P2 may be a particular example of P1. Procedure P3 may beused to enable a wireless device measurement on the same Tx beam (shownas shaded oval in P3), for example, to change a wireless device Rx beamif the wireless device 2401 uses beamforming.

Based on a wireless device's beam management report, a base station maytransmit, to the wireless device, a signal indicating that one or morebeam pair links are the one or more serving beams. The base station maytransmit PDCCH and/or PDSCH for the wireless device using the one ormore serving beams.

A wireless device 2401 (e.g., a UE) and/or a base station 2402 (e.g., agNB) may trigger a beam failure recovery mechanism. The wireless device2401 may trigger a beam failure recovery (BFR) request transmission, forexample, if a beam failure event occurs. A beam failure event mayinclude, for example, a determination that a quality of beam pairlink(s) of an associated control channel is unsatisfactory. Adetermination of an unsatisfactory quality of beam pair link(s) of anassociated channel may be based on the quality falling below a thresholdand/or an expiration of a timer.

The wireless device 2401 may measure a quality of beam pair link(s)using one or more reference signals (RS). One or more SS blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DM-RSs) of a PBCH may be used as a RS for measuring a quality of a beampair link. Each of the one or more CSI-RS resources may be associatedwith a CSI-RS resource index (CRI). A quality of a beam pair link may bebased on one or more of an RSRP value, reference signal received quality(RSRQ) value, and/or CSI value measured on RS resources. The basestation 2402 may indicate whether an RS resource, for example, that maybe used for measuring a beam pair link quality, is quasi-co-located(QCLed) with one or more DM-RSs of a control channel. The RS resourceand the DM-RSs of the control channel may be QCLed when the channelcharacteristics from a transmission via an RS to the wireless device2401, and the channel characteristics from a transmission via a controlchannel to the wireless device, are similar or the same under aconfigured criterion.

A wireless device may monitor a PDCCH, such as a New Radio PDCCH(NR-PDCCH), on M beam pair links simultaneously, where M≥1 and themaximum value of M may depend at least on the wireless devicecapability. Such monitoring may increase robustness against beam pairlink blocking. A base station may transmit, and the wireless device mayreceive, one or more messages configured to cause the wireless device tomonitor NR-PDCCH on different beam pair link(s) and/or in differentNR-PDCCH OFDM symbol.

A base station may transmit higher layer signaling, and/or a MAC controlelement (MAC CE), that may comprise parameters related to a wirelessdevice Rx beam setting for monitoring NR-PDCCH on multiple beam pairlinks. A base station may transmit one or more indications of a spatialQCL assumption between a first DL RS antenna port(s) and a second DL RSantenna port(s). The first DL RS antenna port(s) may be for one or moreof a cell-specific CSI-RS, device-specific CSI-RS, SS block, PBCH withDM-RSs of PBCH, and/or PBCH without DM-RSs of PBCH. The second DL RSantenna port(s) may be for demodulation of a DL control channelSignaling for a beam indication for a NR-PDCCH (e.g., configuration tomonitor NR-PDCCH) may be via MAC CE signaling, RRC signaling, DCIsignaling, or specification-transparent and/or an implicit method, andany combination thereof.

For reception of unicast DL data channel, a base station may indicatespatial QCL parameters between DL RS antenna port(s) and DM-RS antennaport(s) of DL data channel A base station may transmit DCI (e.g.,downlink grants) comprising information indicating the RS antennaport(s). The information may indicate the RS antenna port(s) which maybe QCLed with DM-RS antenna port(s). A different set of DM-RS antennaport(s) for the DL data channel may be indicated as a QCL with adifferent set of RS antenna port(s).

If a base station transmits a signal indicating a spatial QCL parametersbetween CSI-RS and DM-RS for PDCCH, a wireless device may use CSI-RSsQCLed with DM-RS for a PDCCH to monitor beam pair link quality. If abeam failure event occurs, the wireless device may transmit a beamfailure recovery request, such as by a determined configuration.

If a wireless device transmits a beam failure recovery request, forexample, via an uplink physical channel or signal, a base station maydetect that there is a beam failure event, for the wireless device, bymonitoring the uplink physical channel or signal. The base station mayinitiate a beam recovery mechanism to recover the beam pair link fortransmitting PDCCH between the base station and the wireless device. Thebase station may transmit one or more control signals, to the wirelessdevice, for example, after or in response to receiving the beam failurerecovery request. A beam recovery mechanism may be, for example, an L1scheme, or a higher layer scheme.

A base station may transmit one or more messages comprising, forexample, configuration parameters for an uplink physical channel and/ora signal for transmitting a beam failure recovery request. The uplinkphysical channel and/or signal may be based on at least one of thefollowing: a non-contention based PRACH (e.g., a beam failure recoveryPRACH or BFR-PRACH), which may use a resource orthogonal to resources ofother PRACH transmissions; a PUCCH (e.g., beam failure recovery PUCCH orBFR-PUCCH); and/or a contention-based PRACH resource. Combinations ofthese candidate signal and/or channels may be configured by a basestation.

A base station may send a confirmation message to a wireless device, forexample, after or in response to the base station receiving one ormultiple BFR requests. The confirmation message may comprise the CRIassociated with the candidate beam the wireless may indicate in the oneor multiple BFR requests. The confirmation message may comprise an L1control information.

LTE-Advanced introduced Carrier Aggregation (CA) in Release-10. InRelease-10 CA, the Primary Cell (PCell) is always activated. In additionto the PCell, a base station may transmit one or more RRC messagecomprising configuration parameters for one or more secondary cells. In3GPP LTE/LTE-A specification, there are many RRC messages used for Scellconfiguration/reconfiguration. For example, the base station maytransmit a RRCconnectionReconfiguration message for parametersconfiguration of one or more secondary cells for a wireless device,wherein the parameters may comprise at least: cell ID, antennaconfiguration, CSI-RS configuration, SRS configuration, PRACHconfiguration, etc.

The one or more SCells configured in the RRC message can be activated ordeactivated by at least one MAC Control Element (MAC CE). The SCellactivation/deactivation processes were introduced to achieve batterypower savings. After an SCell is deactivated, the wireless device maystop receiving downlink signals and stop transmission on the SCell. InLTE-A specification, the default state of an SCell is deactivated if theSCell has been configured/added. Additional activation procedureemploying MAC CE Activation Command may be needed to activate the SCell.SCells may be deactivated either by an activation/deactivation MAC CE orby the sCellDeactivationTimer. The wireless device and base stationmaintain one sCellDeactivationTimer per SCell with a common value acrossSCells. A base station maintains the activation/deactivation status ofan SCell for a wireless device. The same initial timer value may applyto each instance of the sCellDeactivationTimer and it is configured byRRC. sCellDeactivationTimer is included in Mac-MainConfig dedicatedparameter in an RRC message. The configured SCells may be initiallydeactivated upon addition and after a handover.

The activation/deactivation MAC control element may be used in a varietyof ways. The activation/deactivation MAC control element may beidentified by a MAC PDU subheader, for example, with a pre-assignedLCID. The activation/deactivation MAC CE may have a fixed size, such asa single octet comprising seven C-fields and one R-field as shown inFIG. 25A and FIG. 27B. The activation/deactivation MAC control elementmay comprise field indicating by Ci. If there is an SCell configuredwith SCellIndex i, Ci may indicate the activation/deactivation status ofthe SCell with SCellIndex i, else the MAC entity may ignore the Cifield. The Ci field may be set to a value of “1” to indicate that theSCell with SCellIndex i may be activated. The Ci field may be set to avalue of “0” to indicate that the SCell with SCellIndex i may bedeactivated. The field R may correspond to a reserved bit, which may beset to a value of “0”. If a wireless device is configured with a largernumber of carriers (e.g., more than 5 or 7 carriers), theactivation/deactivation MAC CE may comprise more than one byte, whichmay comprise a longer bitmap such as shown in FIG. 25B.

Deactivation timer management processes may be performed. For example,if a PDCCH on the activated SCell indicates an uplink grant or adownlink assignment; or if a PDCCH on a serving cell scheduling theactivated SCell indicates an uplink grant or a downlink assignment forthe activated SCell: the wireless device may restart ansCellDeactivationTimer associated with the SCell. A MAC entity may(e.g., for each TTI and for each configured SCell) perform certainfunctions related to activation and/or deactivation of one or moreSCells. If the MAC entity receives an activation/deactivation MAC CEactivating the SCell in a TTI, the MAC entity may: activate the SCell;start or restart the sCellDeactivationTimer associated with the SCell;and/or trigger PHR. If the MAC entity receives anactivation/deactivation MAC CE deactivating the SCell in a TTI, or ifthe sCellDeactivationTimer associated with the activated SCell expiresin the TTI, the MAC entity may: deactivate the SCell; stop thesCellDeactivationTimer associated with the SCell; and/or flush all HARQbuffers associated with the SCell.

If a wireless device activates the SCell, the wireless device mayperform SCell operations including: SRS transmissions on the SCell; CQI,PMI, rank indicator (RI), and/or precoding type indicator (PTI)reporting for the SCell; PDCCH monitoring on the SCell; and/or PDCCHmonitoring for the SCell. If the SCell is deactivated, a wireless devicemay perform the following actions: not transmit SRSs on the SCell; notreport CQI, PMI, RI, and/or PTI for the SCell; not transmit on an UL-SCHon the SCell; not transmit on a RACH on the SCell; not monitor the PDCCHon the SCell; not monitor the PDCCH for the SCell. For an SCell that isself-scheduled (e.g., by a PDCCH transmitted on the SCell), the wirelessdevice may not monitor the PDCCH on the SCell if the SCell isdeactivated. For an SCell that is cross-carrier scheduled by a servingcell (e.g., a cell other than the SCell), the wireless device may notmonitor the PDCCH for the SCell if the SCell is deactivated. If an SCellis deactivated, the ongoing random access procedure on the SCell, ifany, may be aborted.

If a wireless device receives a MAC activation command for a secondarycell in subframe n, the corresponding actions in the MAC layer may beapplied no later than a minimum time period (e.g., such as indicated in3GPP TS 36.133) and no earlier than a maximum time period (e.g.,subframe n+8), except for the following: the actions related to CSIreporting and the actions related to the sCellDeactivationTimerassociated with the secondary cell, which may be applied in the maximumtime period (e.g., subframe n+8). If a wireless device receives a MACdeactivation command for a secondary cell or the sCellDeactivationTimerassociated with the secondary cell expires in subframe n, thecorresponding actions in the MAC layer may apply no later than theminimum time period (e.g., such as indicated in 3GPP TS 36.133), exceptfor the actions related to CSI reporting which may be applied in themaximum time period (e.g., subframe n+8).

If a wireless device receives a MAC activation command for a secondarycell in subframe n, the actions related to CSI reporting and the actionsrelated to the sCellDeactivationTimer associated with the secondarycell, may be applied in subframe n+8. If a wireless device receives aMAC deactivation command for a secondary cell or other deactivationconditions are met (e.g., the sCellDeactivationTimer associated with thesecondary cell expires) in subframe n, the actions related to CSIreporting may be applied in subframe n+8. FIG. 26 shows an exampletimeline for a wireless device receiving a MAC activation command. Thewireless device may start or restart the sCellDeactivationTimer in then^(th) subframe, if the wireless device receives a MAC activationcommand in the n^(th) subframe, such as shown in parts “(a)” and “(b)”of FIG. 26. The wireless device may start reporting invalid (e.g., asshown in part “(a)”) or valid (e.g., as shown in part “(b)”) CSI for theSCell at the (n+8)^(th) subframe, if the wireless device receives a MACactivation command in the n^(th) subframe. A wireless device (e.g.,having slow activation) may report an invalid CSI (e.g., out-of-rangeCSI) at the (n+8)^(th) subframe, such as shown in part “(a)” of FIG. 26.The wireless device may start reporting a valid CSI for the SCell as alater subframe, such as subframe n+8+k, as shown in part “(a)”. Awireless device (e.g., having a quick activation) may report a valid CSIat the (n+8)^(th) subframe, such as shown in part “(b)” of FIG. 26.

If a wireless device receives a MAC activation command for an SCell insubframe n, the wireless device may start reporting CQI, PMI, RI, and/orPTI for the SCell at subframe n+8, and/or the wireless device may startor restart the sCellDeactivationTimer associated with the SCell atsubframe n+8. The sCellDeactivationTimer may be maintained in both thebase station and the wireless device, wherein both wireless device andbase station may stop, start, and/or restart this timer in the same TTI.Without such maintaining of the timer, the sCellDeactivationTimer in thewireless device may not be in-sync with the correspondingsCellDeactivationTimer in the base station. The base station may startmonitoring and/or receiving CSI (e.g., CQI, PMI, RI, and/or PTI)according to a predefined timing in the same TTI and/or after wirelessdevice starts transmitting the CSI. If the CSI timings in wirelessdevice and base station are not coordinated, for example, based on acommon standard or air interface signaling, the network operation mayresult in inefficient operations and/or errors.

A base station may transmit, via a PDCCH, a DCI for scheduling decisionand power-control commands. The DCI may comprise one or more of:downlink scheduling assignments, uplink scheduling grants, orpower-control commands. The downlink scheduling assignments may compriseone or more of: PDSCH resource indication, transport format, HARQinformation, control information related to multiple antenna schemes, ora command for power control of the PUCCH used for transmission ofACK/NACK based on or in response to downlink scheduling assignments. Theuplink scheduling grants may comprise one or more of: PUSCH resourceindication, transport format, HARQ related information, or a powercontrol command of the PUSCH.

Different types of control information may correspond to different DCImessage sizes. Supporting spatial multiplexing with noncontiguousallocation of RBs in the frequency domain may require a largerscheduling message in comparison with an uplink grant that may allowonly frequency-contiguous allocation. The DCI may be categorized intodifferent DCI formats (e.g., such as in an LTE system), where a formatmay correspond to a certain message size and/or usage. Table 2 belowprovides a summary of example DCI formats, including the size for anexample of a 20 MHz FDD operation with two Tx antennas at the basestation 2602 and no carrier aggregation.

A wireless device may monitor one or more PDCCH to detect one or moreDCI with one or more DCI formats. The one or more PDCCH may betransmitted in common search space or wireless device-specific searchspace. The wireless device may monitor PDCCH with only a limited set ofDCI format, for example, to save power consumption. The wireless devicemay not be required to detect a DCI with DCI format 6, which may be usedfor an eMTC wireless device. The wireless device may consume more powerbased on the number of DCI formats to be detected. The more DCI formatsto be detected, the more power may be consumed by the wireless device.

The one or more PDCCH candidates that a wireless device monitors may bedefined in terms of PDCCH wireless device-specific search spaces. APDCCH wireless device-specific search space at CCE aggregation levelL∈{1, 2, 4, 8} may be defined by a set of PDCCH candidates for CCEaggregation level L. For a DCI format, a wireless device may beconfigured per serving cell by one or more higher layer parameters anumber of PDCCH candidates per CCE aggregation level L.

DCI Example size format (Bits) Usage Uplink 0 45 Uplink scheduling grant4 53 Uplink scheduling grant with spatial multiplexing 6-0A, 46, 36Uplink scheduling grant for eMTC 6-0B devices Downlink 1C 31 Specialpurpose compact assignment 1A 45 Contiguous allocation only 1B 46Codebook-based beamforming using CRS 1D 46 MU-MIMO using CRS 1 55Flexible allocations 2A 64 Open-loop spatial multiplexing using CRS 2B64 Dual-layer transmission using DM-RS (TM8) 2C 66 Multi-layertransmission using DM-RS (TM9) 2D 68 Multi-layer transmission usingDM-RS (TM9) 2 67 Closed-loop spatial multiplexing using CRS 6-1A, 46, 36Downlink scheduling grants for 6-1B eMTC devices Special 3, 3A 45 Powercontrol commands 5 Sidelink operation 6-2 Paging/direct indication foreMTC devices

Information in the DCI formats that may be used for downlink schedulingmay be organized into different groups. One or more fields of the DCIformats may comprise one or more of: resource information, such as acarrier indicator (e.g., 0 or 3 bits) and/or a RB allocation; a HARQprocess number; an MCS, new data indicator (NDI), and/or RV (e.g., forthe first TB and/or for the second TB); MIMO related information such asPMI, precoding information, a transport block swap flag, a power offsetbetween PDSCH and a reference signal, a reference-signal scramblingsequence, a number of layers, and/or a number of antenna ports for atransmission; PDSCH resource-element mapping and/or QCI; downlinkassignment index (DAI); a transmit power control (TPC) for PUCCH; a SRSrequest (e.g., 1 bit), that may comprise an indication of or trigger fora one-shot SRS transmission; an ACK and/or NACK offset; a DCI formatindication, for example, which may be used to differentiate between DCIformat 1A and DCI format 0 or other formats that may have the samemessage size; and/or padding (e.g., if necessary).

Information in the DCI formats that may be used for uplink schedulingmay be organized into different groups. One or more fields of the DCIformats may comprise one or more of: resource information, such as acarrier indicator, resource allocation type, and/or a RB allocation; anMCS and/or NDI (e.g., for the first TB and/or for the second TB); aphase rotation of the uplink demodulation reference signal (DMRS);precoding information; a CSI request, a request for an aperiodic CSIreport; a SRS request (e.g., 2 bits), that may comprise an indication ofor a trigger for an aperiodic SRS transmission that may use one of up tothree preconfigured settings; an uplink index/DAI; a TPC for PUSCH; aDCI format indication, for example, which may be used to differentiatebetween DCI format 1A and DCI format 0; and/or padding (e.g., ifnecessary).

A base station may perform CRC scrambling on a DCI, for example, beforetransmitting the DCI via a PDCCH. The base station may perform CRCscrambling, for example, by bit-wise addition (or, e.g., modulo-2addition or exclusive OR (XOR) operation) of multiple bits of at leastone wireless device identifier (e.g., C-RNTI, TC-RNTI, SI-RNTI, RA-RNTI,and the like) with the CRC bits of the DCI. The wireless device maycheck the CRC bits of the DCI, if detecting the DCI. The wireless devicemay receive the DCI if the CRC is scrambled by a sequence of bits thatis the same as (or indicates a match with) the at least one wirelessdevice identifier.

A base station may transmit one or more PDCCH in different controlresource sets, for example, which may support wide bandwidth operation.The base station may transmit one or more RRC message comprisingconfiguration parameters for one or more control resource sets. At leastone of the one or more control resource sets may comprise one or moreof: a first OFDM symbol (e.g., CORESET_StartSymbol); a number ofconsecutive OFDM symbols (e.g., CORESET_NumSymbol); a set of resourceblocks (e.g., CORESET_RBSet); a CCE-to-REG mapping (e.g.,CORESET_mapping); and/or a REG bundle size, such as for interleavedCCE-to-REG mapping (e.g., CORESET_REG_bundle). A wireless device maymonitor PDCCH to detect a DCI on a subset of control resource sets(e.g., if control resource sets are configured). Such monitoring mayreduce power consumption by the wireless.

A base station may transmit one or more messages comprisingconfiguration parameters for one or more active bandwidth parts (BWPs).The one or more active BWPs may have different numerologies. The basestation may transmit, to a wireless device, control information forcross-BWP scheduling.

FIG. 27 shows an example of multiple BWP configurations. One or moreBWPs may overlap with one or more other BWPs in a frequency domain. Forexample, BWP 1 may overlap BWP 3, both of which may overlap BWP 4 andBWP 5; BWP 2 may overlap BWP 4; and/or BWP 4 may overlap BWP 5. One ormore BWPs may have a same central frequency with one or more other BWPs.For example, BWP 1 may have a same central frequency as BWP 3.

A base station may transmit one or more messages comprisingconfiguration parameters for one or more DL BWPs and/or one or more ULBWPs for a cell. The one or more BWPs may comprise at least one BWP asthe active DL BWP or the active UL BWP, and/or zero or one BWP as thedefault DL BWP or the default UL BWP. For a PCell, the active DL BWP maybe the DL BWP on which the wireless device may monitor one or more PDCCHand/or receive PDSCH. The active UL BWP may be the UL BWP on which thewireless device may transmit an uplink signal. For an SCell, the activeDL BWP may be the DL BWP on which the wireless device may monitor one ormore PDCCH and receive PDSCH when the SCell is activated, for example,by receiving an activation/deactivation MAC CE. The active UL BWP may bethe UL BWP on which the wireless device may transmit PRACH and/or PUCCH(e.g., if configured) and/or PUSCH if the SCell is activated, forexample, by receiving an activation/deactivation MAC CE.

Configuration of multiple BWPs may be used to reduce a wireless devicepower consumption. A wireless device configured to use an active BWP anda default BWP may switch to the default BWP, for example, if there is noactivity on the active BWP. A default BWP may be configured to use anarrow bandwidth, and/or an active BWP may be configured to use a widebandwidth. If there is no signal transmitting on or receiving from anactive BWP, the wireless device may switch the BWP to the default BWP,which may reduce power consumption.

Switching a BWP may be triggered by a DCI and/or a timer. If a wirelessdevice receives a DCI indicating DL BWP switching from an active BWP toa new BWP, the wireless device may monitor PDCCH and/or receive PDSCH onthe new BWP, for example, after or in response to receiving the DCI. Ifthe wireless device receives a DCI indicating UL BWP switching from anactive BWP to a new BWP, the wireless device may transmit PUCCH (e.g.,if configured) and/or PUSCH on the new BWP, for example, after or inresponse to receiving the DCI.

A base station may transmit, to a wireless device, one or more RRCmessages comprising a BWP inactive timer. The wireless device may startthe timer, for example, if it switches its active DL BWP to a DL BWPother than the default DL BWP. The wireless device may restart the timerto the initial value, for example, if it successfully decodes a DCI toschedule PDSCH(s) in its active DL BWP. The wireless device may switchits active DL BWP to the default DL BWP, for example, if the BWP timerexpires.

FIG. 28 shows an example of BWP switching associated with a BWP inactivetimer. A wireless device may receive one or more RRC messages comprisingparameters for an SCell and one or more BWP configuration associatedwith the SCell. Among the one or more BWPs, at least one BWP may beconfigured as the first active BWP (e.g., BWP 1), and/or one BWP may beconfigured as the default BWP (e.g., BWP 0). The wireless device mayreceive a MAC CE to activate the SCell at the n^(th) subframe. Thewireless device may start or restart the sCellDeactivationTimer at then^(th) subframe, and may start action related to CSI reporting for theSCell, or for the initial active BWP of the SCell, at the (n+8)^(th)subframe. The wireless device may start the BWP inactive timer and/orrestart the sCellDeactivationTimer (e.g., if the wireless devicereceives a DCI indicating switching a BWP from BWP 1 to BWP 2), at the(n+8+k)^(th) subframe. If the wireless device receives a PDCCHindicating a DL scheduling on BWP 2, for example, at the (n+8+k+m)^(th)subframe, the wireless device may restart the BWP inactive timer and/orthe wireless device may restart the sCellDeactivationTimer. The wirelessdevice may switch back to the default BWP (e.g., BWP 0) if the BWPinactive timer expires, for example, at the (n+8+k+m+1)^(th) subframe.The wireless device may deactivate the SCell if thesCellDeactivationTimer expires, for example, at the (n+8+k+m+l+o)^(th)subframe.

The BWP inactive timer may be applied in a PCell. A base station maytransmit one or more RRC messages comprising a BWP inactive timer to awireless device. The wireless device may start the timer if the wirelessdevices switches its active DL BWP to a DL BWP other than the default DLBWP. The wireless device may restart the timer to the initial value ifit successfully decodes a DCI to schedule PDSCH(s) in its active DL BWP.The wireless device may switch its active DL BWP to the default DL BWPif the BWP timer expires.

The BWP inactive timer may be used to reduce wireless device powerconsumption, for example, if the wireless device is configured withmultiple cells and at least one cell has a wide bandwidth. For example,the wireless device may transmit on or receive from a narrow-bandwidthBWP on the PCell or SCell if there is no activity on an active BWP. Thewireless device may deactivate the SCell, which may be triggered bysCellDeactivationTimer expiring, if there is no activity on the SCell.

CSI reporting and/or semi-persistent (SP) CSI reporting may be activatedand/or deactivated by a MAC CE. The MAC CE may comprise a BWP identifierwhich may reduce activation time delay that may otherwise occur for BWPswitching. The MAC CE comprising a BWP identifier may enable a basestation flexibility in transmitting the MAC. The MAC CE comprising a BWPidentifier may reduce downlink data scheduling delay. The MAC CEcomprising a BWP identifier may increase spectrum efficiency of downlinkdata transmission. If activation of CSI reporting is transmitted afteractivation of a cell, the activation may be slow. For example, a MAC CEmay not be transmitted in a time urgent manner, which may result in adelayed CSI report activation. Activation of BWPs, however, may berequired to be relatively quick. For example, BWP activation and/or BWPswitching may be based on physical layer switching. BWPs may be used fortime-sensitive communications. A base station may determine a CSIreporting delay above a threshold may be unacceptable for scheduling ona BWP. By indicating a BWP in a MAC CE prior to BWP activation and/orBWP switching, CSI reporting activation delay may be reduced. A basestation may transmit, to a wireless device, a MAC CE on a first BWP toactivate one or more CSI resources on a second BWP indicated by the BWPidentifier.

A base station may transmit, to a wireless device, one or more RRCmessages comprising configuration parameters for a cell. The cell maycomprise a PCell, an SCell (e.g., an SCell of a plurality of SCells).The configuration parameters may comprise one or more BWPs comprising atleast a first BWP, and/or one or more CSI report configurationscomprising at least a first CSI report configuration. The one or moreCSI report configurations may be associated with a semi-persistent CSIreporting on a physical uplink control channel (PUCCH). The at least afirst BWP may be associated with one or more of: a first parameter for afrequency location, a second parameter for a bandwidth, a thirdparameter for a subcarrier spacing, and/or a fourth parameter for acyclic prefix. A value associated with the second parameter for abandwidth may be less than a value associated with a bandwidth of thecell.

The base station may transmit, to the wireless device, a first MAC CEcomprising: a BWP identifier field indicating the first BWP; and achannel state information (CSI) report configurationactivation/deactivation field indicating activation of the first CSIreport configuration. The activation/deactivation field may comprise anactivation command and/or a deactivation command Additionally oralternatively, the MAC CE may comprise a BWP identifier field indicatingthe first BWP; a semi-persistent (SP) CSI reference signal (CSI-RS)resource set; and/or an indicator indicating activation of the SP CSI-RSresource set. The BWP identifier may comprise any number of bits, suchas, for example, 1, 2, 3, or 4 bits. The MAC CE may comprise a fixedand/or predetermined length. The at least a first CSI reportconfiguration may be associated with one or more of: a reportconfiguration type indicator (e.g., indicating a periodic,semi-persistent, or aperiodic report configuration); reference signalresource configuration parameters; report quantity parameters; frequencydomain configuration parameters; and/or time domain configurationparameters. The one or more CSI reports may be based on: one or morereference signal resources indicated by the one or more reference signalresource parameters; and/or one or more frequency configurationparameters indicated by the one or more report frequency domainconfiguration parameters. The one or more CSI reports may comprise atleast one of the one or more report quantities indicated by the one ormore report quantity parameters.

The wireless device may receive the one or more RRC messages. Thewireless device may receive the first MAC CE. The wireless device mayactivate the first CSI report configuration for the first BWP, forexample, after or in response to receiving the first MAC CE. Thewireless device may activate the first CSI report configuration via aBWP, for example, including via a BWP for the CSI reporting or via anyother BWP. Additionally or alternatively, the wireless device mayactivate the SP CSI-RS resource set for the first BWP, for example,after or in response to receiving the first MAC CE. The wireless devicemay activate the SP CSI-RS resource set via a BWP, for example,including via a BWP for the SP CSI-RS resource set or via any other BWP.The wireless device may activate SP CSI reporting via a physical uplinkcontrol channel (PUCCH). The wireless device may transmit, to the basestation, one or more CSI reports based on the first CSI reportconfiguration. Additionally or alternatively, the wireless device maytransmit, to the base station, one or more CSI reports based on the SPCSI-RS resource set. The wireless device may transmit the one or moreCSI reports via an uplink control channel (e.g., a physical uplinkcontrol channel) and/or via a physical uplink shared channel. The uplinkcontrol channel and/or the physical uplink shared channel may beassociated with the first CSI report configuration. The wireless devicemay transmit the one or more CSI reports with periodic, semi-persistent,or aperiodic transmission indicated by the report configuration typeindicator. The wireless device may transmit, via an uplink controlchannel, the one or more CSI reports with semi-persistent transmissionbased on or in response to the report configuration type indicatorindicating semi-persistent transmission. The wireless device maytransmit, via a physical uplink shared channel, the one or more CSIreports with aperiodic transmission based on or in response to thereport configuration type indicator indicating aperiodic transmission.The one or more CSI reports may comprise one or more of: a firstparameter associated with a channel quality indicator; a secondparameter associated with a precoding matrix index; a third parameterassociated with a rank indicator; and/or a fourth parameter associatedwith a layer 1 reference signal received power.

The base station may transmit, to the wireless device, a second MAC CEcomprising a second BWP identifier field indicating the first BWP; and aCSI report configuration activation/deactivation field indicating adeactivation of the first CSI report configuration. Additionally oralternatively, the base station may transmit, to the wireless device, asecond MAC CE comprising a second BWP identifier field indicating thefirst BWP; an SP CSI-RS resource set; and an indicator indicating adeactivation of the SP CSI-RS resource set. The wireless device mayreceive the second MAC CE. The wireless device may deactivate the firstCSI report configuration for the first BWP, for example, after or inresponse to receiving the second MAC CE. The wireless device maydeactivate the first CSI report configuration via a BWP, for example,including via a BWP for the deactivation of the first CSI reportconfiguration or via any other BWP. Additionally or alternatively, thewireless device may deactivate the SP CSI-RS resource set for the firstBWP, for example, after or in response to receiving the second MAC CE.The wireless device may deactivate the SP CSI-RS resource set via a BWP,for example, including via a BWP for the deactivation of the SP CSI-RSresource set or via any other BWP. The wireless device may stop thetransmission of the one or more CSI reports, for example, after or inresponse to the deactivating.

A base station may transmit one or more RRC message comprising one ormore CSI configuration parameters. The one or more CSI parameters maycomprise one or more: CSI-RS resource setting; CSI reporting settingsand/or CSI measurement setting. A CSI-RS resource setting may compriseone or more CSI-RS resource sets. A CSI-RS resource set may be providedfor a periodic CSI-RS, (P CSI-RS) and/or a semi-persistent (SP) CSI-RS.A base station may transmit one or more P CSI-RS and/or SP CSI-RS with aconfigured periodicity in a time domain. The base station may transmitthe one or more SP CSI-RS with a limited transmission duration that maybe configured by the base station. The base station may transmit the oneor more SP CSI-RS for the wireless device, for example, prior to oruntil the base station deactivates the one or more SP CSI-RS. The basestation may deactivate and/or stop transmission of the one or more SPCSI-RS, for example, by transmitting a SP CSI-RS deactivation MAC CEand/or DCI.

A CSI-RS resource set may comprise one or more of: CSI-RS type (e.g.,periodic, aperiodic, semi-persistent); CSI-RS resources (e.g.,comprising at a CSI-RS resource configuration identity and/or a numberof CSI-RS ports); CSI RS configuration (e.g., a symbol and/or RElocations in a subframe); CSI RS subframe configuration (e.g., subframelocation, offset, and/or periodicity in a radio frame); CSI-RS powerparameter; CSI-RS sequence parameter; CDM type parameter; frequencydensity; transmission comb; and/or QCL parameters.

One or more CSI-RS resources may be transmitted periodically, usingaperiodic transmission, using a multi-shot transmission, or using asemi-persistent transmission. In a periodic transmission, the configuredCSI-RS resource may be transmitted using a configured periodicity in atime domain. In an aperiodic transmission, the configured CSI-RSresource may be transmitted, for example, in a dedicated time slot orsubframe. In a multi-shot transmission or semi-persistent transmission,the configured CSI-RS resource may be transmitted within a configuredperiod.

One or more CSI reporting settings may comprise one or more of: a reportconfiguration identifier; a report type; reported CSI parameter(s); CSItype (e.g., a type I or a type II); codebook configuration; time-domainbehavior; frequency granularity for CQI and/or PMI; and/or measurementrestriction configurations. The report type may indicate a time domainbehavior of the report (e.g., aperiodic, semi-persistent, or periodic).The one or more CSI reporting settings may comprise one or more of: aperiodicity parameter; a duration parameter; and/or an offset (e.g., inunit of slots and/or subframes), for example, if the report type in aCSI reporting setting is a periodic report or a semi-persistent report.The periodicity parameter may indicate the periodicity of a CSI report.The duration parameter may indicate a duration of CSI reporttransmission. The offset parameter may indicate a value of a timingoffset of a CSI report.

An SP CSI report may comprise multiple CSI reporting settings. An SP CSIreport may comprise one CSI resource set for an SP CSI-RS. A CSImeasurement setting may comprise one or more links comprising one ormore link parameters. A link parameter may comprise one or more of: aCSI reporting setting indication, a CSI-RS resource setting indication,and/or measurement parameters. A base station may trigger a CSIreporting, for example, by transmitting am RRC message, a MAC CE, and/ora DCI, such as shown in FIG. 30.

A wireless device may transmit one or more SP-CSI reporting. The one ormore SP-CSI reporting may be transmitted with a transmissionperiodicity. The one or more SP-CSI reporting may be triggered by thewireless device receiving a MAC CE, and/or DCI. The MAC CE or the DCImay indicate an SP-CSI reporting on one or more periodic (P) CSI-RSresources. The MAC CE or the DCI may indicate an SP-CSI reporting on oneor more SP CSI-RS resources.

FIG. 29 shows an example of SP-CSI reporting. A base station maytransmit, to a wireless device, one or RRC messages comprisingconfiguration parameters. The configuration parameters may comprise, forexample, one or more SP-CSI RS configurations. The base station maytransmit, to the wireless device (e.g., at subframe n) a MAC CE and/or aDCI. The MAC CE and/or the DCI may comprise an indication of an SP CSIreporting activation. The wireless device may perform CSI measurement,for example, at subframe n+k. The base station may start transmitting(e.g., at the start of a CSI-RS transmission window) one or more SPCSI-RS at subframe n+k, for example, if the base station transmits atsubframe n a MAC CE and/or DCI to trigger an SP CSI reporting. The valuek may be zero, or an integer greater than zero. The value k may beconfigured in an RRC message and/or the value k may be predefined as afixed value. The wireless device may transmit (e.g., during an SP-CSI RStransmission period) SP CSI reporting at subframe n+k+m, n+k+m+l, and/orn+k+m+2*l, n+k+m+3*l, etc., for example, with a periodicity of lsubframes. The wireless device may stop transmitting SP CSI reporting,for example, after or in response to receiving a MAC CE and/or DCI fordeactivating SP CSI reporting (e.g., which may end a CSI-RS transmissionwindow). The value “m” may be configured with a RRC and/or may bepredefined as a fixed value (e.g., zero or a value greater than zero).

A wireless device may be configured to monitor a downlink channel (e.g.,NR-PDCCH) via one or more beam pair links (BPLs). The number of the oneor more BPLs may be determined at least based on wireless devicecapability. This may increase robustness against BPL blocking. A basestation may transmit one or more messages indicating (and/or causing) awireless device to monitor a downlink channel (e.g., NR-PDCCH) ondifferent BPLs in different symbols (e.g., NR-PDCCH OFDM symbols).

A base station may transmit (e.g., via higher layer signaling and/or aMAC CE) parameters indicating at least one wireless device receive beam(Rx beam) setting for monitoring a downlink channel (e.g., NR-PDCCH) onmultiple BPLs. The base station may transmit an indication of spatialQCL assumption between an DL RS antenna port(s) (e.g., cell-specificCSI-RS, wireless device-specific CSI-RS, SS block, or PBCH with orwithout DM-RSs of PBCH), and DL RS antenna port(s) for demodulation of aDL control channel. Signaling for a beam indication for a downlinkchannel (e.g., NR-PDCCH) may comprise MAC CE signaling, RRC signaling,DCI signaling, or a combination thereof.

For reception of a unicast DL data channel, a base station may transmitone or more of a MAC CE, an RRC message, and/or DCI indicating spatialQCL parameters between DL RS antenna port(s) and DM-RS antenna port(s)of DL data channel. The base station may transmit DCI (e.g., downlinkgrants) comprising one or more parameters indicating the RS antennaport(s). The one or more parameters may indicate the RS antenna port(s)that are QCL-ed with DM-RS antenna port(s). A different set of DM-RSantenna port(s) for the DL data channel may be indicated as QCL with adifferent set of RS antenna port(s).

A wireless device may measure and/or determine a quality of one or moreBPLs using one or more reference signals (RSs). One or more SS blocks,one or more CSI-RSs, and/or one or more DM-RSs may be used to measureand/or determine a quality of a BPL. A base station may configure awireless device with one or more RS resources, used for measuring BPLquality, QCLed (Quasi-Co-Located) with DM-RSs (demodulation referencesignal) of a control channel. The one or more RS resources and theDM-RSs of the control channel may be semi-statically QCLed by the basestation.

A wireless device may detect a beam failure, for example, if the qualityof all BPLs associated with one or more serving control channels fallsbelow a threshold (e.g., in comparison with a threshold, and/or time-outof an associated timer). The threshold may be semi-statically configuredby the base station and/or may be predefined. The quality of BPL may bedefined as hypothetical downlink channel BLER (e.g., PDCCH BLER). Awireless device may be configured with single or multiple BPLs tomonitor the wireless device-specific downlink channel (e.g., PDCCH). Abeam failure may be detected, for example, if the quality of beamassociated with a single BPL downlink channel (e.g., PDCCH) falls belowthe threshold. A beam failure may be detected, for example, if thequality of the beams associated with the multiple BPL downlink channel(e.g., PDCCH) falls below the threshold. The wireless device may measureand/or determine the hypothetical BLER of one or more CSI-RS resourcesand/or SS blocks that are configured as the spatial QCL reference foreach wireless device-specific downlink channel (e.g., PDCCH) and comparethe BLER of one or more CSI-RS resources and/or SS blocks with thecorresponding hypothetical BLER threshold. The wireless device maydetect a beam failure of the downlink channel (e.g., PDCCH), forexample, if the BLER is higher than the threshold.

FIG. 30A shows an example of a beam failure event involving a singleTRP. A single TRP such as at a base station 3001 may send, to a wirelessdevice 3002 (e.g., a UE), a first beam 3003 and a second beam 3004. Abeam failure event may occur if, for example, a serving beam, such asthe second beam 3004, is blocked by a moving vehicle 3005 or otherobstruction (e.g., building, tree, land, or any object) and configuredbeams (e.g., the first beam 3003 and the second beam 3004), includingthe serving beam, are received from the single TRP. The wireless device3002 may trigger a mechanism to recover from beam failure if a beamfailure occurs.

FIG. 30B shows an example of a beam failure event involving multipleTRPs. Multiple TRPs, such as at a first base station 3011 and at asecond base station 3016, may send, to a wireless device 3012 (e.g., aUE), a first beam 3013 (e.g., from the first base station 3011) and asecond beam 3014 (e.g., from the second base station 3016). A beamfailure event may occur if and/or when, e.g., a serving beam, such asthe second beam 3014, is blocked by a moving vehicle 3015 or otherobstruction (e.g., building, tree, land, or any object) and configuredbeams (e.g., the first beam 3013 and the second beam 3014) are receivedfrom multiple TRPs. The wireless device 3012 may trigger a mechanism torecover from beam failure if any/or when a beam failure occurs.

FIG. 31 shows an example of a downlink beam failure recovery procedurecomprising at least one of: a beam failure detection 3104, a newcandidate beam identification 3105, a beam failure recovery requesttransmission 3106, and/or a beam failure recovery request response 3107.

A wireless device 3101 (e.g., a UE) may receive, from a base station3102, one or more resource configuration parameters at step 3101. Thewireless device 3101 may determine a new candidate beam to transmit abeam failure recovery request to notify a network, for example, after orin response to a beam failure detection. The wireless device 3101 mayidentify, based on a beam failure detection 3104 and/or a resourceconfiguration 3103, at least one candidate beam to send a beam failurerecovery request transmission 3106 to the base station 3102. Thewireless device 3101 may select an RS (e.g., the RS may be associatedwith a SSB or CSI-RS) as the at least one candidate beam, for example,if the RSRP of the RS is higher than a threshold. The wireless device3101 may select a new beam identification RS (e.g., SSB only, CSI only,or SSB+CSI-RS) as a new candidate beam, for example, if the RSRP of thenew beam identification RS is higher than a threshold. The wirelessdevice 3101 may trigger and/or send a beam failure recovery (BFR)request 3106, for example, if the measurement quality of all servingbeams associated with control channels fails, and/or falls below a firstthreshold, and the wireless device 3101 identifies a new candidateserving beam. The RSRP of the new candidate serving beam is higher thana second threshold.

The wireless device 3101 may send a beam failure recovery (BFR) request3106 via an uplink channel or signal (e.g., BFR-PUCCH and/or BFR-PRACH).The uplink channel or signal (e.g., BFR-PRACH) may be one or more radioresources FDM-ed/CDM-ed with PRACH. The base station 3102 may detectthat there is a beam failure event for the wireless device 3101, forexample, by monitoring the downlink physical channel and/or signal. Thebase station 3102 may transmit one or more messages comprisingconfiguration parameters of an uplink physical channel and/or signal forbeam failure recovery request transmission. The uplink physical channeland/or signal may be based on one or more of: a non-contention basedPRACH (e.g., BFR-PRACH) (e.g., which may use a resource orthogonal toresources of other PRACH transmissions); a PUCCH (e.g., BFR-PUCCH);and/or a contention-based PRACH resource. Combinations of thesecandidate channels and/or signals may be configured by the base station3102. Contention-based PRACH may serve as a supplement to acontention-free RACH procedure. The base station 3102 may send, forexample, based on receiving the beam failure recovery request 3106, oneor more DCIs to indicate a successful reception of the beam failurerecovery request 3106. The one or more DCIs may comprise one or morefields indicating at least one of a UL grant, a TPC command, and/or oneor more beam indices. The base station 3102 may semi-staticallyconfigure the wireless device 3101 with one or more parametersindicating the resource configurations of BFR-PUCCH and/or BFR-PRACH. Acontention-based PRACH may serve as supplement to a contention-free RACHprocedure. The wireless device 3101 may fall back to contention-basedPRACH (e.g., if the wireless device 3101 is not configured with anyresources for beam failure recovery) to re-establish connection on theserving cell. The UL active beam may be sufficient, whereas DL activebeams may have poor qualities (e.g., without beam correspondence). Thewireless device 3101 may send the beam failure recovery request 3106 viaa BFR-PUCCH. The beam failure request transmission, which may bePUCCH-based, may be a message carried by PUCCH and/or indicated by thenew identified beam.

A BFR-PRACH may use a resource orthogonal to resources of other PRACHtransmissions (e.g., for initial access). There may be a directassociation between the CSI-RS or SS block resources and dedicatedBFR-PRACH resources. These associations may be indicated by RRCparameters from a serving base station (e.g., the base station 3102),for example, if a wireless device joins a network. With a mappingbetween BFR-PRACH resource (e.g., preamble sequence and/ortime-frequency resources) and corresponding new beam index in the RRCparameter list, the information about identifying a wireless device(e.g., the wireless device 3101) or new transmit beam (Tx beam) may becarried by the beam failure recovery request (e.g., the beam failurerecovery request 3106) implicitly by the BFR-PRACH resource.

FIG. 32 shows an example of BFR-PRACH opportunities to send a beamfailure recovery request. The beam failure recovery request may be sentin time, frequency, and/or sequence domain. The beam failure recoveryrequest may correspond to different beam indexes associated with theCSI-RS or SS blocks. Each BFR-PRACH opportunity may be an opportunity intime, frequency, and/or sequence domain for a wireless device 3206(e.g., a UE) to send a preamble sequence to trigger beam failurerecovery. The RACH resources in the n-th BFR-PRACH time opportunity,T_(n), n=1, . . . 4, spanning different frequency indexes F_(k), k=1, .. . 4, and different cyclic shifts, P_(l), l=1, . . . K_(n), hold a beamcorrespondence relationship with beam “n” (e.g., one of a beam 3201, abeam 3202, a beam 3203, or a beam 3204). A BFR-PRACH resource maydifferentiate from another BFR-PRACH resource in the choice of eitherPRACH time opportunity, frequency index, cyclic shift, and/or acombination of them. A BFR-PRACH resource may be, for example, FDM-ed(e.g., using different frequencies) or CDM-ed (e.g., using differentcyclic shifts) with existing PRACH resources such as initial access.

The wireless device 3206 may trigger beam failure recovery mechanism andselect a dedicated BFR-PRACH resource associated with the identified newbeam to send a wireless device-specific preamble (e.g., based on thewireless device 2106 identifying a new candidate beam by measuringmultiple CSI-RSs and/or SS blocks). The wireless device 3206 may send aBFR-PRACH preamble (e.g., if the wireless device detects the beam 3202in FIG. 32 as a new identified beam) on a RACH resource FDM-ed and/orCDM-ed with the second normal PRACH resource (e.g., “PRACH 2” on theP₁/T₂/F₄ or P_(K)/T₂/F₂ resource). A base station may monitor allBFR-PRACH resources for potential beam failure recovery requesttransmissions. The base station may determine and/or infer (e.g., basedon receiving a valid device-specific preamble for a specific BFR-PRACHresource) a wireless device identity for a wireless device associatedwith the preamble (e.g., wireless device 3206) and the desired beamindex for the wireless device 3206. The base station may determineand/or interpret the beam 3202 as the desired beam index from thewireless device 3206 (e.g., if a device-specific preamble is received ona BFR-PRACH during T₂ in FIG. 32).

The wireless device 3206 may receive a response from the base station(e.g., after the wireless device 3206 has sent a beam failure recoveryrequest). The previous active beams associated with the failed controlchannels may suffer from poor quality (e.g., it may be difficult tomonitor a base station response on those failed beams). The wirelessdevice 3206 may report a new candidate beam with a good RSRP level(e.g., above a threshold such as −3 db, −5 db, or −8 db) in the beamfailure recovery request. The wireless device 3206 may monitor the basestation response on a RRC configured dedicated CORESET associated withthe newly identified beam. The dedicated CORESET is addressed to C-RNTI(e.g., device-specific) and is spatial QCL-ed with DL RS of the wirelessdevice-identified candidate beam reported in the beam failure recoveryrequest transmission. The dedicated CORESET may be used by the networkfor control channel transmission before and/or after beam failureoccurs. The wireless device 3206 may declare the beam failure recoveryrequest is received by the base station correctly and the wirelessdevice 3206 may stop the beam failure recovery request transmission(e.g., based on the UE 3206 detecting a valid wireless device-specificDCI in that dedicated CORESET). The time window to monitor the basestation response may be determined by a fixed time offset (e.g., a 4slot offset that may be RRC configurable starting from a fixed timeoffset).

The wireless device 3206 may not receive a response from the basestation for various reasons. The base station may fail to receive a beamfailure recovery request transmission due to incorrect beam selection asa new beam candidate. The base station may fail to receive a beamfailure recovery request transmission due to a lack of enough wirelessdevice transmission power. The beam failure recovery requesttransmission may not reach the base station, and/or the base station maynot be aware of the failed serving beam(s). The base station responsemay not reach the wireless device 3206 because of an incorrect downlinkbeam for the control channel transmission, or for various other wirelesscommunications issues. A retransmission mechanism for beam recoveryrequest may have the advantage of promoting robust operation. Thewireless device 3206 may send an indicator to a high layer and/or a MAClayer (e.g., based on the wireless device 3206 receiving a response withthen response time window), which may trigger the retransmission of thebeam failure recovery request. The indicator may be carried in the nextavailable channel (PUCCH or non-contention based PRACH). To avoidexcessive retransmissions, a maximum retransmission number N for thebeam recovery request may be configured by the network, and/or may belimited by the number of dedicated uplink beam failure recoveryresources. The wireless device 3206 may declare beam failure recoverymechanism as unsuccessful and/or the wireless device 3206 may stopresending (e.g., based on a number of beam failure recovery requestretransmissions reaching a maximum number and/or a timer expiring). Thewireless device 3206 may refrain from performing a beam recoveryprocedure, send an indication to higher layers, and/or may wait for RLFdeclaration of higher layers.

A wireless device (e.g., a UE) with multiple serving beams configuredfor access to a base station may experience beam failure on only asubset of the serving beams. Beam failure recovery using a beam that isnot a serving beam (e.g., a candidate beam that is not a serving beam)may be inefficient (e.g., it may require a new congestion and/or addtraffic to a beam in use for other devices). The wireless device may useoperational serving beams (e.g., serving beams not of the subset thatfailed) to indicate the subset of failed beams and/or perform beamfailure recovery. This may have the advantage of enabling the wirelessdevice to recover from failed beams and/or avoid having to establish anew connection using a candidate beam if and/or when established servingbeams are available.

FIG. 33 shows an example of a wireless device 3302 configured for beamfailure recovery. One or more parameters may comprise a maximum numberof transmission N_(max), a timer 3310 for stopping a beam failurerecovery procedure, and a timer 3320 (e.g., for a base station responsewindow). The wireless device 3302 may detect a beam failure and identifya new beam. The wireless device 3301 may send a first beam failurerecovery request (BFRQ) transmission (e.g., comprising a BRF-PRACH and aPRACH). The wireless device 3302 may re-send (e.g., in a second BFRQtransmission) the beam recovery request (e.g., based on the wirelessdevice 3302 failing to receive a beam recovery response message from abase station 3301 within the bounds of the timer 3320 and/or after thetransmission of a first beam recovery request). The wireless device 3302may stop the beam failure recovery procedure and/or send an indicationof beam failure recovery failure to higher layers (e.g., if the numberof sending beam recovery request is N_(max) and/or the timer 3310expires). The timer 3310 may start after or in response to one or moreof: the beam failure detection, new candidate beam identification,and/or the first beam failure recovery transmission.

The wireless device 3302 may detect a full beam failure, for example, ifall configured multi-beam serving control channels fail. The wirelessdevice 3302 may detect a partial beam failure wireless device, forexample, if the wireless device 3302 does not detect a beam failure onone or more (e.g., some or all) configured multi-beam. The partial beamfailure may occur, for example, if the wireless device 3302 detects abeam failure on one or more serving beams, but at least one serving beamhas a RSRP higher than a threshold (and/or has a BLER lower than athreshold, which may be different from the threshold for RSRP). Thewireless device 3302 may start a partial beam failure recoveryprocedure, for example, if the wireless device 3302 detects the partialbeam failure.

The partial beam failure may be detected by the wireless device 3302,for example, by monitoring and/or measuring at least one BLER of aCSI-RS and/or a SS block. A partial beam failure recovery procedure maybe initiated by the wireless device 3302 (e.g., based on detecting thepartial beam failure). A base station 3301 may send one or more messagescomprising parameters of one or more physical layer resources for a fulland/or a partial beam failure recovery procedure. The one or morephysical layer resources and/or configuration parameters may comprise atleast one of: DL RS resources to monitor the quality of PDCCH; DL RSresources to identify candidate new beams for the PDCCH; one or more ULchannels to report a full and/or a partial beam failure; and/or one ormore DL channels to response to the wireless device 3302 on beamrecovery.

The one or more physical layer resources and/or the configurationparameters may be common for full beam failure recovery and partial beamfailure recovery procedures. The one or more physical layer resourcesand/or the configuration parameters used to send a full beam failurerecovery request and a partial beam failure recovery request may bedifferent.

One or more UL resources for reporting a partial beam failure recovery(e.g., for a partial beam failure recovery procedure initiated by thewireless device 3302) may be semi-statically and/or dynamicallyconfigured by the base station 3301. The failed beam information may besent, to the base station 3301, for example, via explicit signaling orimplicit signaling. The explicit signaling may be sent via PUCCH and/orvia PUSCH. The explicit signaling may comprise at least one fieldindicating a failed beam index and/or a RS ID related to the failedbeam. Control data and/or UL-SCH data (e.g., sent via PUSCH or viaPUCCH) may have a field indicating the failed beam index and/or the RSID. The implicit signaling may indicate a failed beam index and/or a RSID related to the failed beam by the wireless device 3302 sending atleast one preamble via one or more BFR-PRACHs. The at least one preambleand/or the at least one BFR-PRACH may be associated with the failed beamindex or related RS ID. The base station 3301 may semi-statically and/ordynamically configure the wireless device 3302 with at least oneassociation between the failed beam index, the RS ID, a preamble, and/ora BFR-PRACH.

The wireless device 3302 may send the partial beam failure recoveryrequest via the PUCCH. At least one serving beam configured for PUCCHtransmission, among a plurality of serving beams configured for the PUCHtransmission, may not fail. The wireless device 3302 may send a partialbeam failure recovery request via the at least one serving beam that hasnot failed.

The PUCCH may be scheduled periodically. The PUCCH may not be availableat a time that the wireless device 3302 may detect the partial beamfailure. The PUCCH may be scheduled per one or more beams. The wirelessdevice 3302 may wait (e.g., after detecting a failure) until (e.g.,after) the PUCCH associated with at least one beam of the wirelessdevice is available. Waiting until the PUCCH is available may cause alatency problem.

The wireless device 3302 may report the failed beam index and/or the RSID (e.g., related to the failed beam) via the PUCCH. The base station3301 may need to differentiate (e.g., based on receiving the partialbeam failure recovery request) between the regular PUCCH reporting andthe partial beam failure recovery request transmission. Differentiatingmay utilize a new format and/or may occupy additional PUCCH resources,which may cause increased overhead.

The wireless device 3302 may send at least one preamble via at least oneBFR-PRACH (e.g., if the wireless device 3302 detects a full beamfailure). The at least one preamble and/or at least one BFR-PRACH may beassociated with at least one candidate beam (e.g., at least onecandidate beam identified by the wireless device 3302 as a new servingbeam). The wireless device 3302 may choose not to use a first preambleand/or a first BFR-PRACH associated with one or more serving beams.

The wireless device 3302 may use the first preamble and/or the firstBFR-PRACH to send a partial beam failure recovery request. The basestation 3301 may determine which beams are configured for PUCCHtransmissions (e.g., serving beam for PUCCH transmissions). The basestation 3301 may detect a full beam failure recovery request (e.g.,based on receiving the request via the at least one preamble and/or atleast one BFR-PRACH). The base station 3301 may detect a partial beamfailure recovery request (e.g., based on receiving the request via thefirst one preamble and/or first one BFR-PRACH).

FIG. 34 shows an example of full and partial beam failure recoveryrequest transmissions via BFR-PRACH resources 3405 associated with thecandidate beams (e.g., a candidate beam 3410 and/or a candidate beam3425) and/or serving beams (e.g., serving beam 3420 and/or serving beam3415).

The PUCCH assigned for the partial beam failure recovery request 3403may not be available and/or may not be scheduled frequently. At leastone of the BFR-PRACH resources 3405 may be scheduled before PUCCH (e.g.,if a wireless device 3402 detects a partial beam failure). The wirelessdevice 3402 (e.g., a UE) may send the partial beam failure recoveryrequest 3403 via at least one of the BFR-PRACH resources 3405, which mayreduce latency. The wireless device 3402 may selectively choose a PUCCHand/or at least one of the BFR-PRACH resources 3405. The wireless device3402 may send the partial beam failure recovery request 3403 via PUCCH(e.g., if a transmission window for a PUCCH is available earlier than atransmission window for the at least one of the BFR-PRACH resources3405). The wireless device 3402 may send the partial beam failurerecovery request via the at least one of the BFR-PRACH resources 3405(e.g., if a transmission occasion of the at least one of the BFR-PRACHresources 3405 is available earlier than a transmission occasion ofPUCCH).

The base station 3401 may not expect to receive a full beam failurerecovery request 3404 via the at least one of the BFR-PRACH resources3405 allocated at least one serving beam (e.g., the serving beam 3420and/or the serving beam 3415). The at least one of the BFR-PRACHresources 3405 corresponding to the at least one serving beam may not beutilized. The base station 3401 may configure (e.g., semi-statically)the wireless device 3402 with the at least one of the BFR-PRACHresources 3405 (which may be dedicated) and/or at least one preamble forthe full beam failure recover request procedure (which may bededicated). Certain radio resources may go unutilized (e.g., may bewasted). Using the at least one of the BFR-PRACH resources 3405 and/orpreamble for the partial beam failure recovery procedure may increase aDL resource utilization and/or a UL resource utilization. The wirelessdevice 3402 may indicate the partial beam failure recovery request 3403(e.g., if the base station 3401 receives, from the wireless device 3402,a dedicated PRACH preamble via the at least one of the BFR-PRACHresources 3405 associated with the one or more serving beams). A fullbeam failure recovery request 3404 may be indicated by the base station3401 receiving a dedicated PRACH preamble on the non-serving beam.

The partial beam failure recovery request via the at least one of theBFR-PRACH resources 3405 may indicate a failure of at least one beam(e.g., the serving beam 3420 and/or the serving beam 3415). The basestation 3401 may initiate (e.g., based on receiving the partial beamfailure recovery request 3402) the partial beam failure recoveryprocedure (e.g., one of P1, P2, P3, U1, U2, and/or U3 with SS blockand/or CSI-RS) on the at least one serving beam. The base station 3401may send one or more aperiodic CSI-RS for the wireless device 3402 touse in identifying at least one new candidate beam. The base station3401 may or may not reconfigure a TCI state if or after the full and/orpartial beam failure recovery procedure is complete.

The base station 3401 may send, to the wireless device 3402, at leastone message comprising at least one of following: first parametersindicating configuration of one or more reference signals (CSI-RS and/orSS blocks) associated with a plurality of serving beams (e.g., theserving beam 3420 and/or the serving beam 3415), wherein the pluralityof serving beams may be associated with sending downlink channel (e.g.,PDCCH); second parameters indicating the at least one of the resources(e.g., BFR-PRACH resources 3405) for the partial beam failure recoveryrequest 3403; and/or third parameters indicating one or moreassociations between at least one reference signal and/or the at leastone of the resources (e.g., BFR-PRACH resources 3405). The wirelessdevice 3402 may detect a partial beam failure (e.g., on the at least onefirst reference signal) based on a first threshold. The wireless device3402 may select (e.g., based on detection the partial beam failure) asecond reference signal different from the at least one referencesignal. The second reference signal may be selected based on a selection(e.g., a random selection) from reference signals of the at least onereference signal. The second reference signal may send (e.g., via afirst RACH resource associated with the second reference signal) a firstpreamble indicating the partial beam failure.

FIG. 35 shows an example of a partial beam failure recovery. A wirelessdevice 3502 (e.g., a UE) may be configured with at least one downlinkchannel (e.g., PDCCH) transmission via at least one BPL (e.g., a beam3510, a beam 3520, a beam 3530, and/or a beam 3540, which may be fourserving beams configured for the at least one downlink channeltransmission). The wireless device 3502 may detect a beam failure (e.g.,on the beam 3510 and/or the beam 3520). The beam failure may be detectedbased on detecting a quality (e.g., a quality of RSRP and/or BLER) ofthe beam 3510 and/or the beam 3520 falling below a threshold. The beamfailure may be due to a wireless device rotation, a movement, and/or ablockage of the wireless device 3502. After and/or during the beamfailure a quality (e.g., a quality of RSRP and/or BLER) of the beam 3530and/or the beam 3540 may be above the threshold. The beam 3530 and/orthe beam 3540 may be use for transmission (e.g., PDCCH transmission). Atleast one preamble and/or at least one resource (e.g., BFR-PRACHresource, which may be one of the BFR-PRACH resources 3505) configuredfor beams not associated with the partial beam failure (e.g., the beam3530 and/or the beam 3540) may be used for indicating the partial beamfailure. The wireless device 3502 may select (e.g., based on detectingthe partial beam failure) the at least one preamble and/or the at leastone BFR-PRACH resource associated with the beam 3530 and/or the beam3540 to indicate the failure on the beam 3510 and/or the beam 3520 to abase station 3501. The selection may be random. The wireless device 3502may randomly select one of the preambles and or the at least oneBFR-PRACH resource associated with the beam 3530 and/or the beam 3540.The wireless device 3502 may select the one of the preambles and/or theat least one BFR-PRACH resource associated with the beam 3530 and/or thebeam 3540, for example, based on a signal strength and/or BLER. The basestation 3501 may determine, based on detecting a partial beam failurerecovery request 3504, that at least one failure on a beam other thanthe beam 3530 and/or beam 3540 is detected at the wireless device 3502.

FIG. 36 shows an example of a partial beam failure recovery. A wirelessdevice 3602 (e.g., a UE) may be configured with at least one BPL (e.g.,a beam 3610, a beam 3620, a beam 3630, and/or a beam 3640) to monitor aPDCCH associated with the wireless device 3602. The wireless device 3602may detect a partial beam failure on a plurality of the beam 3610, thebeam 3620, and/or the beam 3630, wherein the quality of the failed beamsmay be below a threshold and the quality of the beam 3640 may be abovethe threshold. The wireless device 3602 may indicate the partial beamfailure (e.g., based on detecting the partial beam failure) by sending afirst preamble via a first RACH resource (which may be of the BFR-PRACHresources 3605) associated with the beam 3640. The first preamble may besent in a partial beam failure recovery request 3604. The base station3601 may detect (e.g., based on receiving the first preamble of thefirst RACH resource associated with the beam 3640) the failure on thebeam 3610, the beam 3620, and/or the beam 3630.

A selection of at least one preamble and/or at least one BFR-PRACHresource (which may be of the BFR-PRACH resources 3605) may bepredefined or semi-statically configured, for example, by the basestation 3601. A mapping may associate the at least one preamble and/orthe at least one BFR-PRACH resource with at least one failed beam and/orwith at least one beam selected as a new candidate beam.

FIG. 37 shows an example of a partial beam failure. A wireless device(e.g., a UE) may be configured with at least two serving beams, forexample, a serving beam 3701 and a serving beam 3702. A base station3710 may configure the wireless device with at least two preambles(e.g., P₁ and P₂) and at least two BFR-PRACH resource sets (e.g., T₁/F₁and T₂/F₂) for a partial beam failure recovery request. There may be oneor more example selection schemes (scenarios, rules, and/or tables) toselect one of preambles and BFR-PRACHs. Preambles and/or BFR-PRACHresources may be configured (e.g., semi-statically) and/or preconfigured(or predefined) to indicate a failure of a beam. FIG. 37 may show fourexample selection schemes. In a selection scheme 3711, the wirelessdevice may send the preamble P₁ via BFR-PRACH T₁ and F₁ to indicate apartial beam failure if the serving beam 3701 has failed. In theselection scheme 3711, the wireless device may send the preamble P₂ viaBFR-PRACH T₂ and F₂ to indicate a partial beam failure if the servingbeam 3702 has failed. In an example selection scheme 3712, the wirelessdevice may send the preamble P₂ via BFR-PRACH T₁ and F₁ to indicate apartial beam failure if the serving beam 3701 has failed. In a selectionscheme 3712, the wireless device may send the preamble P₁ via BFR-PRACHT₂ and F₂ to indicate a partial beam failure if the serving beam 3702has failed. In a selection scheme 3713, the wireless device may send thepreamble P₂ via BFR-PRACH T₂ and F₂ to indicate a partial beam failureif the serving beam 3701 has failed. In the selection scheme 3713, thewireless device may send the preamble P₁ via BFR-PRACH T₁ and F₁ toindicate a partial beam failure if the serving beam 3702 has failed. Ina selection scheme 3714, the wireless device may send the preamble P₁via BFR-PRACH T₂ and F₂ to indicate a partial beam failure if theserving beam 3701 has failed. In the selection scheme 3714, the wirelessdevice may send the preamble P₂ via BFR-PRACH T₁ and F₁ to indicate apartial beam failure if the serving beam 3702 has failed.

FIG. 38 and FIG. 39 show examples of a partial beam failure. A wirelessdevice (e.g., a UE) may be configured with three serving beams. A basestation 3810 may configure the wireless device with at least threepreambles (e.g., P₁, P₂, and P₃) and at least three BFR-PRACH resourcesets (e.g., T₁/F₁, T₂/F₂, and T₃/F₃) for a partial beam failure recoveryrequest. There may be one or more example selection schemes (scenarios,rules, and/or tables) to select one of preambles and BFR-PRACHs.Preambles and/or BFR-PRACH resources may be configured (e.g.,semi-statically) and/or preconfigured (or predefined) to indicate afailure of a beam.

FIG. 38 shows two example selection schemes. In a selection scheme 3811,the wireless device may send the preamble P₃ via BFR-PRACH T₁ and F₁ toindicate a partial beam failure if a serving beam 3803 has failed. Inthe selection scheme 3811, the wireless device may send the preamble P₂via BFR-PRACH T₁ and F₁ to indicate a partial beam failure if a servingbeam 3802 has failed. In the selection scheme 3811, the wireless devicemay send the preamble P₁ via BFR-PRACH T₂ and F₂ to indicate a partialbeam failure if a serving beam 3801 has failed. In the selection scheme3811, the wireless device may send the preamble P₃ via BFR-PRACH T₃ andF₃ to indicate a partial beam failure if the serving beam 3801 and theserving beam 3802 have failed. In the selection scheme 3811, thewireless device may send the preamble P₂ via BFR-PRACH T₂ and F₂ toindicate a partial beam failure if the serving beam 3801 and the servingbeam 3803 have failed. In the selection scheme 3811, the wireless devicemay send the preamble P₁ via BFR-PRACH T₁ and F₁ to indicate a partialbeam failure if the serving beam 3802 and the serving beam 3803 havefailed.

In a selection scheme 3812, the wireless device may send the preamble P₃via BFR-PRACH T₂ and F₂ to indicate a partial beam failure if theserving beam 3803 has failed. In the selection scheme 3812, the wirelessdevice may send the preamble P₂ via BFR-PRACH T₃ and F₃ to indicate apartial beam failure if the serving beam 3802 has failed. In the exampleselection scheme 3812, the wireless device may send the preamble P₁ viaBFR-PRACH T₃ and F₃ to indicate a partial beam failure if the servingbeam 3801 has failed. In the selection scheme 3812, the wireless devicemay send the preamble P₃ via BFR-PRACH T₃ and F₃ to indicate a partialbeam failure if the serving beam 3801 and the serving beam 3802 havefailed. In the selection scheme 3812, the wireless device may send thepreamble P₂ via BFR-PRACH T₂ and F₂ to indicate a partial beam failureif the serving beam 3801 and the serving beam 3803 have failed. In theselection scheme 3812, the wireless device may send the preamble P₁ viaBFR-PRACH T₁ and F₁ to indicate a partial beam failure if the servingbeam 3802 and the serving beam 3803 have failed.

The base station 3810 may send, to a wireless device, one or moremessages comprising at least one of: first parameters indicatingconfiguration of one or more reference signals (CSI-RS and/or SS blocks)associated with a plurality of serving beams (e.g., the serving beam3801, the serving beam 3802, and/or the serving beam 3803), wherein theplurality of serving beams may be associated with sending PDCCH; secondparameters indicating one or more RACH resources for a beam failurerecovery request; and/or third parameters indicating one or moreassociations between at least one of the one or more reference signalsand at least one of the one or more RACH resources. The wireless devicemay detect a partial beam failure based on a first threshold, on atleast one first reference signal of a plurality of reference signalsassociated with the plurality of serving beams. The wireless device mayselect, based on detecting the partial beam failure, a second referencesignal having a highest received signal strength among the plurality ofreference signals associated with the serving beams and is differentfrom the at least one reference signal. The wireless device may send,via a first RACH resource associated with the second reference signal, afirst preamble indicating the partial beam failure.

FIG. 39 shows two example election schemes. In as selection scheme 3911,the wireless device may send the preamble P₁ via BFR-PRACH T₃ and F₃ toindicate a partial beam failure if a serving beam 3903 has failed. Inthe selection scheme 3911, the wireless device may send the preamble P₁via BFR-PRACH T₂ and F₂ to indicate a partial beam failure if a servingbeam 3902 has failed. In the selection scheme 3911, the wireless devicemay send the preamble P₂ via BFR-PRACH T₁ and F₁ to indicate a partialbeam failure if a serving beam 3901 has failed. In the selection scheme3911, the wireless device may send the preamble P₃ via BFR-PRACH T₁ andF₁ to indicate a partial beam failure if the serving beam 3901 and theserving beam 3902 have failed. In the selection scheme 3911, thewireless device may send the preamble P₂ via BFR-PRACH T₁ and F₁ toindicate a partial beam failure if the serving beam 3901 and the servingbeam 3903 have failed. In the selection scheme 3911, the wireless devicemay send the preamble P₁ via BFR-PRACH T₂ and F₂ to indicate a partialbeam failure if the serving beam 3902 and the serving beam 3903 havefailed.

In a selection scheme 3912, the wireless device may send the preamble P₂via BFR-PRACH T₃ and F₃ to indicate a partial beam failure if theserving beam 3903 has failed. In the selection scheme 3912, the wirelessdevice may send the preamble P₃ via BFR-PRACH T₂ and F₂ to indicate apartial beam failure if the serving beam 3902 has failed. In theselection scheme 3912, the wireless device may send the preamble P₃ viaBFR-PRACH T₁ and F₁ to indicate a partial beam failure if the servingbeam 3901 has failed. In the selection scheme 3912, the wireless devicemay send the preamble P₃ via BFR-PRACH T₂ and F₂ to indicate a partialbeam failure if the serving beam 3901 and the serving beam 3902 havefailed. In the selection scheme 3912, the wireless device may send thepreamble P₂ via BFR-PRACH T₃ and F₃ to indicate a partial beam failureif the serving beam 3901 and the serving beam 3903 have failed. In theselection scheme 3912, the wireless device may send the preamble P₁ viaBFR-PRACH T₃ and F₃ to indicate a partial beam failure if the servingbeam 3902 and the serving beam 3903 have failed.

The base station 3910 may send, to a wireless device (e.g., to a UE), atleast one message comprising at least one of: first parametersindicating configuration of one or more reference signals (CSI-RS and/orSS blocks) associated with a plurality of serving beams (e.g., theserving beam 3901, the serving beam 3902, and/or the serving beam 3903),wherein the plurality of serving beams may be associated with sendingPDCCH; second parameters indicating one or more RACH resources for abeam failure recovery request; and/or third parameters indicating one ormore associations between at least one of the one or more referencesignals and at least one of the one or more RACH resources. The wirelessdevice 3910 may detect a partial beam failure based on a firstthreshold, on at least one first reference signal of a plurality ofreference signals associated with the plurality of serving beams. Thewireless device 3910 may select, based on detecting the partial beamfailure, a second reference signal having a highest received signalstrength among the plurality of reference signals associated with theserving beams and is different from the at least one reference signal.The wireless device 3910 may send, via a first RACH resource associatedwith the second reference signal, a first preamble indicating thepartial beam failure.

FIG. 40 shows an example of a partial beam failure recovery. A wirelessdevice 4002 (e.g., a UE) may be configured with at least one PDCCHtransmission via at least one BPL (e.g., a beam 4011, a beam 4012, abeam 4013, and/or a beam 4014, which may be four serving beamsconfigured for the at least one PDCCH transmission). The wireless device4002 may detect a beam failure (e.g., on the beam 4011 and/or the beam4012). The beam failure may be detected based on detecting a quality(e.g., a quality of RSRP and/or BLER) of the beam 4011 and/or the beam4012 falling below a threshold 4017. The beam failure may be due to arotation, a movement, and/or a blockage of the wireless device 4002.After and/or during the beam failure a quality (e.g., a quality of RSRPand/or BLER) of the beam 4013 and the beam 4014 may be above thethreshold. The beam 4013 and/or the beam 4014 may be used for downlinkchannel (e.g., PDCCH) transmission. The preamble and/or BFR-PRACH (whichmay be one of the BFR-PRACH resources 4005) configured for beams notassociated with the partial beam failure (e.g., the beam 4013 and/or thebeam 4014) may be used for indicating the partial beam failure. Thewireless device 4002 may select (e.g., based on detecting the partialbeam failure) at least one preamble and/or at least one BFR-PRACHresource (which may be of the BFR-PRACH resources 4005) associated withthe beam 4013 and/or the beam 4014 to indicate the failure on the beam4011 and/or the beam 4012 to a base station 4001. The wireless device4002 may select the at least one preamble and/or the at least oneBFR-PRACH resource associated with the beam 4013 and/or the beam 4014based on a signal strength and/or BLER. The wireless device 4002 mayselect the at least one of the preambles and/or the at least oneBFR-PRACH resource associated with beam 4013, which may have the highestRSRP. The base station 4001 may identify, based on detecting the partialbeam failure recovery request 440, that at least one failure on a beamother than beam 4013 is detected at the wireless device 4002.

The base station 4001 may send, to the wireless device 4002, at leastone message comprising at least one of: first parameters indicatingconfiguration of one or more reference signals (CSI-RS and/or SS blocks)associated with a plurality of serving beams (e.g., the beam 4011, thebeam 4012, the beam 2013, and/or the beam 4014), wherein the pluralityof serving beams may be associated with sending PDCCH; second parametersindicating one or more RACH resources for a beam failure recoveryrequest; and/or third parameters indicating one or more associationsbetween at least one of the one or more reference signals and at leastone of the one or more RACH resources. The wireless device 4010 maydetect a partial beam failure based on a first threshold (e.g.,threshold 4017), on at least one first reference signal of a pluralityof reference signals associated with the plurality of serving beams. Thewireless device 4010 may select, based on detecting the partial beamfailure, a second reference signal based on a random selection fromamong the plurality of reference signals associated with the servingbeams. The wireless device 4002 may send, via a first RACH resourceassociated with the second reference signal, a first preamble indicatingthe partial beam failure.

FIG. 41 shows an example of a partial beam failure recovery. A wirelessdevice 4102 (e.g., a UE) may be configured with at least one PDCCHtransmission via four BPLs (e.g., a beam 4111, a beam 4112, a beam 4113,and/or a beam 4114, which may be four serving beams configured for theat least one PDCCH transmission). The wireless device 4102 may detect abeam failure (e.g., on the beam 4111 and/or the beam 4112). The beamfailure may be detected based on detecting a quality (e.g., a quality ofRSRP and/or BLER) of the beam 4111 and/or the beam 4112 falling below athreshold. The beam failure may be due to a rotation, a movement, or ablockage of the wireless device 4102. Following and/or during the beamfailure a quality (e.g., a quality of RSRP and/or BLER) of the beam 4113and the beam 4114 may be above the threshold. The beam 4113 and/or thebeam 4114 may be employed for PDCCH transmission. The preamble and/orBFR-PRACH (which may be one of the BFR-PRACH resources 4105) configuredfor beams associated with the partial beam failure (e.g., the beam 4111and/or the beam 4112) may be employed for indicating the partial beamfailure. The wireless device 4102 may select (e.g., based on detectingthe partial beam failure) one or more the preambles and/or at least oneBFR-PRACH resource (which may be of the BFR-PRACH resources 4105)associated with the beam 4111 and/or the beam 4112 to indicate thefailure on the beam 4111 and/or the beam 4112 to a base station 4101.The selection may be random. The wireless device 4102 may randomlyselect one of the preambles and or the at least one BFR-PRACH resourceassociated with the beam 4111 and/or the beam 4112. The wireless device4102 may select the one of the preambles and/or the at least oneBFR-PRACH resource associated with the beam 4111 and/or the beam 4112based on a signal strength and/or BLER. The base station 4101 mayidentify, based on detecting a partial beam failure recovery request4104, that at least one failure on the beam 4111 and/or beam 4111 isdetected at the wireless device 4102.

The base station 4101 may send, to the wireless device 4102, at leastone message comprising at least one of: first parameters indicatingconfiguration of one or more reference signals (CSI-RS and/or SS blocks)associated with a plurality of serving beams (e.g., the beam 4111, thebeam 4112, the beam 4113, and/or the beam 4114), wherein the pluralityof serving beams may be associated with sending PDCCH; second parametersindicating one or more RACH resources for beam failure recovery request;and/or third parameters indicating one or more associations between atleast one of the one or more reference signals and at least one of theone or more RACH resources. The wireless device 4101 may detect apartial beam failure based on a first threshold, on at least one firstreference signal of a plurality of reference signals associated with theplurality of serving beams. The wireless device 4102 may select, basedon detecting the partial beam failure, a second reference signal havinga highest received signal strength from among the plurality of referencesignals. The wireless device 4102 may send, via a first RACH resourceassociated with the second reference signal, a first preamble indicatingthe partial beam failure.

FIG. 42 shows an example of a partial beam failure recovery. A wirelessdevice 4202 (e.g., a UE) may be configured with at least one PDCCHtransmission via four BPLs (a beam 4211, a beam 4212, a beam 4213,and/or a beam 4214, which may be four serving beams configured for theat least one PDCCH transmission). The wireless device 4202 may detect abeam failure (e.g., on the beam 4211 and the beam 4212). The beamfailure may be detected based on detecting a quality (e.g., a quality ofRSRP and/or BLER) of the beam 4211 and/or the beam 4212 falling below athreshold 4217. The beam failure may be due to a wireless devicerotation, movement, and/or blockage of the wireless device 4202. Afterand/or during the beam failure a quality (e.g., a quality of RSRP and/orBLER) of the beam 4213 and/or the beam 4214 may be above the threshold4217. The beam 4213 and the beam 4214 may be employed for PDCCHtransmission. At least one preamble and/or at least one BFR-PRACHresource (which may be one of the BFR-PRACH resources 4205) configuredfor beams associated with the partial beam failure (e.g., the beam 4211and/or the beam 4212) may be employed for indicating the partial beamfailure. The wireless device 4202 (e.g., based on detecting the partialbeam failure) may select the at least one preamble and/or the at leastone BFR-PRACH resource associated with beam 4211 and/or beam 4212 toindicate the failure on beam 4211 and/or beam 4212 to the base station4201. The wireless device 4202 may select the at least one preambleand/or the at least one BFR-PRACH resource associated with beam 4211and/or beam 4212 based on a signal strength and/or BLER. The wirelessdevice 4202 may select the at least one preamble and/or the at least oneBFR-PRACH resource associated with beam 4212, which may have the highestRSRP among the beams associated with the partial beam failure. The basestation 4201 may identify, based on detecting the partial beam failurerecovery request 4204, that at least one failure on beam 4212 isdetected at the wireless device 4202.

FIG. 43 shows an example of partial beam failure recovery. At step 4301,a wireless device (e.g., a UE) may receive (e.g., from a base station)configuration parameters for a partial beam failure recovery procedure.The configuration parameters may comprise parameters for configuring aplurality of serving beams, at least one RACH resource (which may beassociated with the plurality of serving beams), a predeterminedthreshold for beam failure, and/or a mapping rule. The mapping rule mayassociate a selection scheme (such as the example selection schemesdepicted in FIG. 37, FIG. 38, and/or FIG. 39) with the serving beams.

At step 4305, the wireless device may monitor the plurality of servingbeams, for example, to determine if a beam failure has occurred. Thebeam failure may be detected based on detecting a quality (e.g., aquality of RSRP and/or BLER) of at least one serving beam of theplurality of serving beams and/or the quality of the at least oneserving beam falling below the predetermined threshold. At step 4305,the wireless device may determine if a subset of the plurality ofserving beams has failed. A failure of the subset may comprise a failureof the at least one serving beam with at least one other serving beam ofthe plurality of serving beams not failing. If the subset has failed,the wireless device may proceed with initiating a partial beam failurerecovery procedure at step 4315. The wireless device may determine if afull beam failure has occurred at step 4320 (e.g., if all serving beamsof the plurality of serving beams have failed), which may cause thewireless device to proceed with full beam failure recovery at step 4325.If no failure is detected, the wireless device may continue to monitorthe plurality of serving beams at step 4305

At step 4315, the wireless device may initiate partial beam failurerecovery (e.g., using systems or methods as described herein). At step4320, the wireless device may select a serving beam of the plurality ofserving beams for beam recovery. The selected serving beam may be aserving beam with a quality above the predetermined threshold. Theselected serving beam may be randomly selected. The selected servingbeam may be selected based on the mapping rule. At step 4325, thewireless device may send a preamble via the at least one RACH resource.The preamble may be sent using the selected serving beam (and/or a RACHresource associated with the selected serving beam). The preamble mayindicate the beam failure regarding the subset of the plurality ofserving beams.

FIG. 44 shows an example of partial beam failure recovery. At step 4401,a base station may send (e.g., to a wireless device) configurationparameters for a partial beam failure recovery procedure. Theconfiguration parameters may comprise parameters for configuring aplurality of serving beams, at least one RACH resource (which may beassociated with the plurality of serving beams), a predeterminedthreshold for beam failure, a mapping rule, and/or other parameters usedin beam failure recovery. The mapping rule may associate a selectionscheme (such as the example selection schemes depicted in FIG. 37, FIG.38, and/or FIG. 39) with the serving beams.

At step 4405, the base station may monitor the plurality of servingbeams, for example, to determine if a beam failure has occurred. At step4410, the base station may detect a partial beam failure recoveryrequest, which may indicate that a subset of the plurality of servingbeams has failed. A failure of the subset may comprise a failure of theat least one serving beam with at least one other serving beam of theplurality of serving beams not failing.

At step 4415, the base station may receive (e.g., from the wirelessdevice) a preamble indicating the beam failure. The preamble mayindicate the failed subset and/or a selected beam for beam failurerecovery. The selected serving beam may be a serving beam with a qualityabove the predetermined threshold. The selected serving beam may berandomly selected. The selected serving beam may be selected based onthe mapping rule. The preamble may be received by the at least one RACHresource, which may be assigned based on the mapping rule. The preamblemay be sent using the selected serving beam (and/or a RACH resourceassociated with the selected serving beam). The preamble may indicatethe beam failure regarding the subset of the plurality of serving beams.At step 4420, the base station may complete BFR, such as using thesystems or methods described herein.

Candidate beams selected based on a highest RSRP may cause additionallatency, congestion, and/or beam failure (e.g., because the high RSRPmay cause a large number of devices to connect to the candidate beam,causing overload and/or beam failure). A wireless device (e.g., a UE)may identify new candidate beams (e.g., the candidate beam and/or areplacement candidate beam if the initial candidate beam fails) based onone or more other criteria (which may be in addition to RSRP). Thewireless device may determine the replacement candidate beam based onone or more of a time criterion and/or a frequency criterion. Thewireless device may select a particular criterion to determine thereplacement candidate, for example, based on a mobility level of awireless device (e.g., above or below a speed threshold) and/or based onan interference level of a wireless device (e.g., above or below aninterference threshold). If a wireless device is above a first mobilitylevel (and/or if a wireless device is below a first interference level),a replacement candidate may be determined based on a time criterion. Ifa wireless device is above a second interference level (and/or if awireless device is below a second mobility level), a replacementcandidate may be determined based on a frequency criterion.

The wireless device may determine the replacement candidate beam basedon a time criterion (e.g., the replacement candidate beam may bebroadcast a threshold time after the initial/previous candidate beam).Beams may be broadcast in a “sweep” by a base station, so beamsbroadcast close together may be directed in a similar direction. Waitinga threshold time may have the advantage of selecting the replacementcandidate beam directed to a different direction than theinitial/previous candidate beam. This may have the advantage ofcompensating for the wireless device moving at high speed, as beamsdirected similarly to the initial/previous candidate beam may not bedirected toward the wireless device if the wireless device isdisconnected due to being moved.

The wireless device may determine the replacement candidate beam basedon a frequency criterion. In a high interference environment,frequencies for multiple RSs may overlap and cause interference, and/orexternal interference (e.g., microwaves, cordless home phones, or otherwireless devices) may cause interference resulting in beam failure. Thewireless device may select the replacement candidate beam with afrequency that is a threshold distance from a frequency of theinitial/previous candidate beam, which may reduce the probability thatthe replacement candidate beam will not successfully complete BFR due tointerference. The wireless device may use one or more criteria ormethods discussed herein to select the replacement candidate beam (e.g.,the wireless device may randomly select the replacement candidate beamfrom a group of candidate beams meeting the time criterion and thefrequency criterion). The wireless device may then repeat the BFRprocess with the replacement candidate beam.

FIG. 45 shows an example of a plurality of candidate beams beingidentified by a plurality of wireless devices (e.g., UEs). At least onewireless device of the wireless devices 4502 may detect a beam failurebased on measuring at least one reference signal associated with atleast one downlink serving control channel with a BLER higher than afirst threshold. The at least one wireless device may identify (e.g.,based on the beam failure detection) at least one candidate beam (e.g.,at least one of a beam 4511, a beam 4512, a beam 4512, and/or a beam4514) different from the at least one reference signal based on a secondthreshold. The at least one candidate beam may be selected by the atleast one of the wireless devices as a candidate beam. One candidatebeam may be identified by multiple of the wireless devices 4502 (e.g.,due to various wireless device locations and/or the mobility of thewireless devices 4502). Some candidate beams may associate with a largernumber of the wireless devices 4502 than others (e.g., due to variouswireless device locations and/or the mobility of the wireless devices4502). If the beam failure recovery procedure on a beam with a largernumber of the wireless devices 4502 (e.g., the beam 4511) completessuccessfully, a base station 4501 may serve the larger number ofwireless devices 4502 with the at least one candidate beam (e.g., thebeam 4512). Adding the larger number of the wireless devices 4502 maycause an overload problem on the at least one candidate beam due tooversubscription (e.g., scheduling problem of PUSCH, PUCCH, PDSCH,and/or PDCCH).

At least one of the wireless devices 4502, based on a beam failuredetection, may select the beam 4511 as a candidate beam. The at leastone of the wireless devices 4502 may send, based on selecting beam 4511as the candidate beam, a preamble via a BFR-PRACH resource associatedwith the beam 4511 and/or via a BFR-PUCCH resource. The base station4501 may not have enough resources (e.g., PUSCH/PUCCH and/or PDCCH/PDSCHresources) to serve the at least one of the wireless devices 4502 (e.g.,due to high overload on a serving beam). The base station 4501 may useanalog beamforming. The base station 4501 may periodically sweep throughmultiple beams (e.g., from beam 4511 through beam 4514). As the basestation 4501 sweeps through the multiple beams, the base station 4501may progress through beams directed at various angles. Beams broadcastmore closely in time may be directed to more similar angles than beamsbroadcast more distantly in time. Selecting a new candidate beam,broadcast a threshold time after an initial candidate beam, may select abeam that is more likely to broadcast at a sufficiently different angleto connect to the wireless device, for example, if the wireless devicehas moved from a prior location. There may be a delay on UL/DLtransmission to schedule one or more resources for the larger number ofthe wireless devices 4502 (e.g., if the beam 4511 is associated with thelarger number of the wireless devices 4502). The delay may cause a beammanagement procedure on the large number of the wireless devices 4502 todistribute the large number of the wireless devices 4502 to other beams(e.g., from beam 4511 to at least one of beam 4512, beam 4513, and/orbeam 4514), which may introduce latency. The wireless devices 4502 mayuse a beam selection mechanism to identify the candidate beam. The beamselection mechanism may be used to select the candidate beam fromseveral possible candidate beams. The beam selection mechanism may bespecific to the at least one of the wireless devices 4502 and/or may bepredefined. The beam selection mechanism may distribute the wirelessdevices 4502 between each beam (e.g., evenly across beam 4511, beam4512, beam 4513, and/or beam 4514) to avoid overloading a single beam(e.g., beam 4511) and/or to achieve an efficient utilization ofresources.

There may be criteria for selecting a candidate beam during aretransmission of BFRQ triggered for at least one failed beam. The atleast one of the wireless devices 4502 may select a candidate beam(e.g., the beam 4511) based on a received signal strength (e.g., ahighest signal strength among multiple detected beams) and/or a quality(e.g., a quality of RSRP and/or BLER). The at least one of the wirelessdevices 4502 device may randomly select a candidate beam (e.g., the beam4512). The randomly selected beam may be selected from a plurality ofbeams with a received signal strength and/or a quality exceeding athreshold. The plurality of beams may exclude any failed beams. Theselected beam may be selected using a second threshold (which may bepredefined and/or semi-statically configured) that may based on anallowable backoff value from a beam quality of a previous candidate beam(e.g., a lower beam quality than the quality of the previous candidatebeam).

The at least one of the wireless devices 4502 may receive (e.g., fromthe base station 4501) at least one message comprising: first parametersindicating at least one reference signal (RS); second parametersindicating at least one RACH resource for a beam failure recoveryrequest; and/or third parameters indicating at least one associationbetween at least one of the at least one RS and/or the at least one RACHresource. The at least one of the wireless devices 4502 may send a firstpreamble via a first RACH resource associated with a first RS (e.g.,based on detecting a beam failure). The at least one of the wirelessdevices 4502 may monitor (e.g., during a response window) a PDCCH for aresponse from the base station 4501. The at least one of the wirelessdevices 4502 may select (e.g., based on not detecting a response duringthe response window) a second RS, wherein a difference between a firstreceived signal strength (RSS) of the first RS and a second RSS of thesecond RS exceeding (or failing to exceed) a first threshold. The atleast one of the wireless devices 4502 may send (e.g., based on the RSselection) a second preamble via a second RACH resource. The secondpreamble and the second RACH resource may be associated with the secondRS. The at least one RS may comprise at least one CSI-RS and/or at leastone SS block. A RACH resource (e.g., the at least one RACH resource orthe second RACH resource) may comprise a time resource, a frequencyresource, and/or a preamble. Beam failure may be detected based on areceived signal strength of at least downlink control channels beinglower than a first threshold. Based on the detection, at least onecandidate beam associated with the at least one reference signal may beidentified based on a second threshold. An RSS may be measured based onthe received power of the at least one RS.

FIG. 46 shows an example of a beam selection. A wireless device may beconfigured to measure and/or determine (e.g., based on detecting a beamfailure) a quality (e.g., a quality of RSRP and/or BLER) of one or morecandidate beams (e.g., a beam 4601, a beam 4602, a beam 4603, and/or abeam 4604). The wireless device may identify a first candidate beambased on a quality exceeding a threshold (e.g., the beam 4602, the beam4603, and/or the beam 4604 may be identified based on exceeding thecandidate beam identification threshold 4606). The wireless device maysend (e.g., based on detecting a beam failure) a first preamble via afirst RACH resource associated with a first beam (e.g., the beam 4602).The first beam may be selected based on the first beam having a highestRSRP and/or a lowest BLER among the one or more candidate beams. Thewireless device may select, based on not detecting a response during aresponse window (e.g., the timer 3320 of FIG. 33), a second beam (e.g.,beam the 4603). The wireless device may select the second beam toalleviate an overload problem on the first beam. The wireless device mayemploy a second value (e.g., the RSS difference 4605), which may bepredefined and/or semi-statically configured. The wireless device maydetermine if a difference between a first received signal strength (RSS)of the first beam and a second RSS of the second beam exceeds the firstvalue. The difference exceeding the first value may indicate that thesecond beam is not sufficiently close in quality to the first beam. Thewireless device may send, based on the selection, a second preamble viaa second RACH resource. The second preamble and the second RACH resourcemay be associated with the second beam.

FIG. 47 shows an example of a beam selection. A wireless device (e.g., aUE) may be configured to measure and/or determine (e.g., based ondetecting a beam failure) a quality (e.g., a quality of RSRP and/orBLER) of one or more candidate beams (e.g., a beam 4701, a beam 4702, abeam 4703, and/or a beam 4704). The wireless device may identify a firstcandidate beam based on a quality exceeding a threshold (e.g., the beam4702, the beam 4703, and/or the beam 4704 may be identified based onexceeding the candidate beam identification threshold 4706). Thewireless device may send (e.g., based on detecting the beam failure) afirst preamble via a first RACH resource associated with a first beam(e.g., the beam 4702). The first beam may be selected based on the firstbeam having a highest RSRP and/or a lowest BLER among the one or morecandidate beams. The wireless device may select (e.g., randomly select)(e.g., based on not detecting a response within a response window, suchas the timer 3320 of FIG. 33) a second beam among the one or morecandidate beams whose quality is higher than the threshold (e.g., thewireless device may randomly select the beam 4703 or the beam 4704). Thewireless device may select the second beam based on determining that adifference between a first RSS of the first beam and a second RSS of thesecond beam does not exceed a first value (e.g., the RSS difference4705). The wireless device may select the second beam to alleviate anoverload problem on the first beam. The wireless device may select(e.g., based on not detecting a response within a response window, suchas the timer 3320 of FIG. 33) the second beam among the one or morecandidate beams that have a quality that is higher than the threshold(e.g., the wireless device may randomly select the beam 4703 or the beam4704) and that have a second-highest RSRP and/or a lowest BLER fromamong the one or more candidate beams. The wireless device may send,based on the selection, a second preamble via a second RACH resource.The second preamble and the second RACH resource may be associated withthe second beam. wireless device

The wireless device may receive, from a base station, one or moremessages comprising at least one of: first parameters indicating the atleast one reference signal (RS); second parameters indicating the atleast one RACH resource for a beam failure recovery request; and/orthird parameters indicating at least one association between the atleast one RS and the at least one RACH resource. The wireless device maysend a first preamble via a first RACH resource associated with a firstRS based on detecting a beam failure. The wireless device may monitor(e.g., during a response window, such as the timer 3320 in FIG. 33) aPDCCH for a response from the base station. The wireless device mayselect a second RS (e.g., based on no response being detected during theresponse window) based on a time difference between a first TTI forreceiving the first RS and a second TTI for receiving the second RSexceeding a second threshold. The wireless device may select (e.g.,based on not detecting a response during the response window) the secondRS based on determining that the RSS of the second RS is lower than theRSS of the first RS and higher than the second threshold, and/or basedon determining that the time difference exceeds the second threshold.The wireless device may send, based on the RS selection, a secondpreamble via a second RACH resource, wherein the second preamble and thesecond RACH resource are associated with the second RS.

Criteria may be used to select a candidate beam for use in aretransmission of BFRQ triggered for a failed beam. The wireless devicemay select a candidate beam, for example, based on an RS transmissiontime associated with the candidate beam. The wireless device mayrandomly select a first beam, from one or more beams, as a candidatebeam. The selection may be based on a time difference between an RStransmission time of the one or more beams and an RS transmission timeof a previous candidate beam selected in a previous BFRQ transmissionbeing higher than a time threshold. The time threshold may indicate atime difference in terms of transmission time (e.g., TTI, slot,mini-slot, or symbol value from the transmission time of the previouscandidate beam). The time threshold may provide time diversity and/or adistributed candidate beam selection mechanism. The time threshold maybe useful for UEs with high mobility. A wireless device may select afirst beam for a candidate beam based on the first beam having a highestreceived signal strength and/or a highest quality of the one or morebeams. The one or more beams may comprise beams that have not failed.The one or more beams may comprise beams for which a second timedifference, between an RS transmission time of the one or more beams andthe RS transmission time of the previous candidate beam selected in theprevious BFRQ transmission, exceeds the time threshold.

FIG. 48 shows an example of a beam selection. A wireless device (e.g., aUE) may be configured to measure and/or determine (e.g., based ondetecting a beam failure) a quality (e.g., a quality of RSRP and/orBLER) of one or more candidate beams (e.g., a beam 4801, a beam 4802, abeam 4803, a beam 4804, and/or a beam 4805). The wireless device mayidentify (e.g., based on measuring the beam quality) at least onecandidate beam with a quality that exceeds a threshold (e.g., the beam4802, the beam 4803, the beam 4804, and/or the beam 4805 may beidentified as exceeding a candidate beam identification threshold 4806).The wireless device may send (e.g., based on detecting the beam failure)a first preamble via a first RACH resource associated with a first beam(e.g., the beam 4802). The first beam may be selected based on the firstbeam having a highest RSRP and/or a lowest BLER among the one or morecandidate beams. The wireless device may select (e.g., based on notdetecting a response within a response window, such as the timer 3320 ofFIG. 33) a second beam based on a RSS and/or RS transmission timeassociated with each of the one or more candidate beams. The wirelessdevice may select the second beam based on a quality of the second beamexceeding the candidate beam identification threshold 4802. The wirelessdevice may select the second beam based on determining that adifference, between a first RS transmission time of the first beam and asecond RS transmission time of the second beam, exceeds a timedifference 4807. The wireless device may send, based on the selection, asecond preamble via a second RACH resource. The second preamble and thesecond RACH resource may be associated with the second beam.

FIG. 49 shows an example of a beam selection. A wireless device (e.g., aUE) may be configured to measure and/or determine (e.g., based ondetecting a beam failure) a quality (e.g., a quality of RSRP and/orBLER) of one or more candidate beams (e.g., a beam 4901, a beam 4902, abeam 4903, a beam 4904, and/or a beam 4905). The wireless device mayidentify (e.g., based on measuring the beam quality) at least onecandidate beam with a quality that exceeds a threshold (e.g., the beam4902, the beam 4903, the beam 4904, and/or the beam 4905 may beidentified as exceeding a candidate beam identification threshold 4906).The wireless device may send (e.g., based on detecting the beam failure)a first preamble via a first RACH resource associated with a first beam(e.g., the beam 4902). The first beam may be selected based on the firstbeam having a highest RSRP and/or a lowest BLER among the one or morecandidate beams. The wireless device may select (e.g., based on notdetecting a response within a response window, such as the timer 3320 ofFIG. 33) a second beam based on a RSS and/or RS transmission timeassociated with each of candidate beams. The wireless device mayrandomly select the second beam from a plurality of beams for which aquality exceeds the candidate beam identification threshold 4902 (e.g.,beam the 4904 and/or the beam 4905). The wireless device may select thesecond beam based on determining that a difference between a first RStransmission time of the first beam and a second RS transmission time ofthe second beam exceeds a time difference 4907. The wireless device mayselect the second beam based on the second beam having a highest RSRPand/or a lowest BLER among the one or more candidate beams. The wirelessdevice may select the second beam such that the second beam may be sentoutside the time difference 4907 from the first beam (e.g., the beam4904 exceeds the time difference 4907 from the beam 4902). The wirelessdevice may select the second beam from among multiple beams after thetime difference 4907 based on the highest RSRP (e.g., the beam 4904 hasa higher RSRP than the beam 4905). The wireless device may send, basedon the selection, a second preamble via a second RACH resource. Thesecond preamble and the second RACH resource may be associated with thesecond beam.

The wireless device may receive, from a base station, one or moremessages comprising at least one of: first parameters indicating atleast one reference signal (RS); second parameters indicating at leastone RACH resource for a beam failure recovery request; and/or thirdparameters indicating oat least one association between the at least oneRS and the at least one RACH resource. The wireless device may send afirst preamble via a first RACH resource associated with a first RSbased on detecting a beam failure. The wireless device may monitor(e.g., during a response window) a PDCCH for a response from the basestation. The wireless device may select (based on not detecting aresponse during the response window, such as the timer 3320 in FIG. 33)a second RS, based on determining that the RSS of the second RS may behigher than the RSS of the first RS, and/or based on determining that atime difference between a first TTI for the first RS and a second TTIfor the second RS exceeds a time threshold. Selecting the second RSbased on exceeding the time threshold may have the advantage of avoidingoverload on the first beam and/or providing time diversity.

FIG. 50 shows an example of a beam selection. A wireless device (e.g., aUE) may be configured to measure and/or determine (e.g., based ondetecting a beam failure) a quality (e.g., a quality of RSRP and/orBLER) of one or more candidate beams (e.g., a beam 5001, a beam 5002, abeam 5003, a beam 5004, and/or a beam 5005). The wireless device mayidentify (e.g., based on measuring the beam quality) at least onecandidate beam with a quality that exceeds a threshold (e.g., the beam5002, the beam 5003, the beam 5004, and/or the beam 5005 may beidentified as exceeding a candidate beam identification threshold 5006).The wireless device may send (e.g., based on detecting the beam failure)a first preamble via a first RACH resource associated with a first beam(e.g., the beam 5002). The wireless device may select (e.g., based onnot detecting a response during a response windows, such as the timer3320 of FIG. 33) a second beam based on a RSS and/or an RS transmissiontime associated with each of the one or more candidate beams. Thewireless device may identify the second beam based on a quality of thesecond beam exceeding the candidate beam identification threshold 5006.The wireless device may randomly select the second beam from a pluralityof beams exceeding a time difference 5007 from the first beam (e.g., thebeam 5005 exceeds the time difference 5007 from the beam 5002). Thewireless device may select the second beam from the plurality of beams(e.g., the beams after the time difference 5007) by selecting the beamwith the highest RSRP and/or lowest BLER among the plurality of beams.The wireless device may send, based on the selection, a second preamblevia a second RACH resource. The second preamble and the second RACHresource may be associated with the second beam. wireless device

The wireless device may receive, from a base station, one or moremessages comprising at least one of: first parameters indicating atleast one reference signal (RS); second parameters indicating at leastone RACH resource for a beam failure recovery request; and/or thirdparameters indicating at least one association between the at least oneRS and the at least one RACH resource. The wireless device may send afirst preamble via a first RACH resource associated with a first RSbased on to detecting a beam failure. The wireless device may monitor(e.g., during a response window, such as timer 3320 of FIG. 33) a PDCCHfor a response from the base station. The wireless device may select(e.g., based on not detecting a response during the response window) asecond RS, wherein the second RS has a second-highest RSRP among aplurality of candidate beams (e.g., the beam 5005 may be selectedbecause it has the second-highest RSRP). The selection of the secondbeam with the second-highest RSRP may have the advantage of avoidingoverloading a beam with a highest RSRP (e.g., the beam 5004), which mayhave a large number of connected clients. A quality (e.g., RSRP) of thesecond beam may be enough for successful transmission of a beam failurerecovery request. The wireless device may select (e.g., based on notdetecting a response during the response window) a second RS, whereinthe second RS has a highest RSS among the plurality of candidate beams.The wireless device may send, based on the selection, a second preamblevia a second RACH resource. The second preamble and the second RACHresource may be associated with the second beam.

FIG. 51A and FIG. 51B show examples of beam selections. Criteria may beused to select a candidate beam for use in a retransmission of BFRQtriggered for a failed beam. A wireless device (e.g., a UE) may select acandidate beam based on transmission frequency. The wireless device mayselect a candidate beam based on frequency resources associated with thecandidate beam. The wireless device may randomly select a candidate beamamong candidate beams that are beyond a specified frequency interval(e.g., frequency difference 5106) from a prior candidate beam. Thefrequency interval may indicate a frequency difference in terms of aresource block, a subcarrier, and/or a bandwidth value. The wirelessdevice may select the candidate beam based on determining a group ofbeams outside the frequency interval, and choosing a beam based on acriteria from the group (e.g., selecting a beam with a highest receivedsignal strength and/or highest quality from the group as the candidatebeam). Selecting a beam based on the frequency interval may have theadvantage of avoiding overloading the previous candidate beam and/orproviding frequency diversity.

A wireless device may be configured to measure and/or determine aquality (e.g., a quality of RSRP and/or BLER) of one or more candidatebeams to a base station 5101 (e.g., a beam 5111, a beam 5112, a beam5113, and/or a beam 5114). The wireless device may identify (based onmeasuring the beam quality) at least one candidate beam with a qualitythat exceeds a threshold (e.g., the beam 5112, the beam 5113, and/or thebeam 5114 may be identified as exceeding a candidate beam identificationthreshold 5105). The wireless device may send (e.g., based on detectinga beam failure) a first preamble via a first RACH resource associatedwith a first beam (e.g., the beam 5112). The wireless device may select(e.g., based on not detecting a response within a response window, suchas the timer 3320 of FIG. 33) a second beam based on a RSS and/or a RStransmission frequency associated with each of the one or more candidatebeams. The RS transmission frequency may comprise the frequencyresources used for BFR-PRACH transmission associated with the one ormore candidate beams (e.g., the candidate beams in FIG. 40A and/or FIG.40B). The wireless device may identify one or more beams based ondetermining that a quality of the one or more beams is higher than thecandidate beam identification threshold 5105. The wireless device mayrandomly select one of the one or more beams exceeding a frequencythreshold (e.g., the frequency difference 5106) from a prior beam (e.g.the beam 5114 may exceed the frequency threshold from the beam 5112).The wireless device may select a candidate beam by selecting a beam witha highest RSRP and/or lowest BLER (e.g., not randomly) from among thebeams exceeding the frequency threshold wireless device. The wirelessdevice may send, based on the selection, a second preamble via a secondRACH resource. The second preamble and the second RACH resource may beassociated with the second beam.

Criteria may be used to select a candidate beam during a retransmissionof BFRQ triggered for one or more failed beams. The wireless device mayselect a candidate beam based on received signal strength, quality, RStransmission time, and/or RS transmission frequency. Combining multiplecriteria and/or selection techniques may have the advantage of promotingtime diversity and/or frequency diversity, as well as avoiding beamoverload.

FIG. 52 shows an example of beam failure recovery. A wireless device(e.g., a UE) may receive (e.g., from a base station) configurationparameters for beam failure recovery at step 5201. The configurationparameters may comprise various parameters for beam failure recovery asdiscussed herein (e.g., candidate beams, thresholds, etc.). At step5205, the wireless device may detect a beam failure associated with acell. The wireless device may detect a beam failure based on metricsassociated with a beam (e.g., RSRP) following below a threshold. At step5210, the wireless device may initiate a BFR procedure according to oneor more systems or methods described herein.

At step 5215, the wireless device may select an initial candidate beamfor BFR. The wireless device may determine the candidate beam based onthe configuration parameters. The wireless device may determine theinitial candidate beam based on determining a beam with a highest RSRPfrom a plurality of possible beams. The wireless device may determinethe candidate beam by selecting a random beam from the plurality ofpossible beams. The wireless device may determine the initial candidatebeam by selecting a beam with a second-highest RSRP from the pluralityof possible beams.

At step 5220, the wireless device may send a preamble via an RSassociated with the candidate beam (e.g., the initial candidate beam, ora new candidate beam for a later attempt). At step 5225, the wirelessdevice may determine if a response is received (e.g., using DCI) from abase station. If a response is received, the wireless device maycomplete BFR at step 5230. If no response is received (e.g., after atime threshold), the wireless device may determine the new candidatebeam at step 5235.

At step 5235, the wireless device may determine the new candidate beam.The wireless device may determine the new candidate beam based on a timecriterion (e.g., the new candidate beam may be broadcast a thresholdtime after the initial/previous candidate beam). Beams may be broadcastin a “sweep” by a base station, so beams broadcast close together may bedirected in a similar direction. Waiting a threshold time may have theadvantage of selecting the new candidate beam directed to a differentdirection than the initial/previous candidate beam. This may have theadvantage of compensating for the wireless device moving at high speed,as beams directed similarly to the initial/previous candidate beam maynot be directed toward the wireless device if the wireless devicedisconnected due to being moved. The wireless device may determine thenew candidate beam based on a frequency criterion. In a highinterference environment, frequencies for multiple SRs may overlap andcause interference, and/or external interference (e.g., microwaves,cordless home phones, or other wireless devices) may cause interferenceresulting in beam failure. The wireless device may select the newcandidate beam with a frequency that is a threshold distance from afrequency of the initial/previous candidate beam, which may reduce theprobability that the new candidate beam will not successfully completeBFR due to interference. The wireless device may use one or morecriteria or methods discussed herein to select the new candidate beam(e.g., the wireless device may randomly select the new candidate beamfrom a group of candidate beams meeting the time criterion and thefrequency criterion). The wireless device may then repeat the BFRprocess with the new candidate beam. If the new candidate beam isunsuccessful, the wireless device may repeat step 5235 to select yetanother candidate beam.

In FIG. 53 shows an example of beam failure recovery. At step 5301, abase station may send (e.g., to a wireless device) configurationparameters for a beam failure recovery procedure. The configurationparameters may comprise parameters for selecting a candidate beam, atleast one RACH resource (which may be associated with the candidatebeam), a predetermined threshold for beam failure, and/or otherparameters used in beam failure recovery. The parameters for selecting acandidate beam may comprise criteria such as those discussed in FIG. 45through FIG. 52.

At step 5305, the base station may monitor the plurality of servingbeams to determine if a beam failure has occurred. At step 5310, thebase station may detect a beam failure recovery request. At step 5315,the base station may receive (e.g., from the wireless device) a preambleindicating the beam failure. The preamble may indicate the failed beamand/or a selected candidate beam for beam failure recovery. The selectedcandidate beam may be a serving beam with a quality above thepredetermined threshold. At step 5320, the base station may completeBFR, such as using any of the systems or methods described herein.

FIG. 54 shows general hardware elements that may be used to implementany of the various computing devices discussed herein, including, e.g.,the base station 401, the wireless device 406, or any other basestation, wireless device, or computing device described herein. Thecomputing device 5400 may include one or more processors 5401, which mayexecute instructions stored in the random access memory (RAM) 5403, theremovable media 5404 (such as a Universal Serial Bus (USB) drive,compact disk (CD) or digital versatile disk (DVD), or floppy diskdrive), or any other desired storage medium. Instructions may also bestored in an attached (or internal) hard drive 5405. The computingdevice 5400 may also include a security processor (not shown), which mayexecute instructions of one or more computer programs to monitor theprocesses executing on the processor 5401 and any process that requestsaccess to any hardware and/or software components of the computingdevice 5400 (e.g., ROM 5402, RAM 5403, the removable media 5404, thehard drive 5405, the device controller 5407, a network interface 5409, aGPS 5411, a Bluetooth interface 5412, a WiFi interface 5413, etc.). Thecomputing device 5400 may include one or more output devices, such asthe display 5406 (e.g., a screen, a display device, a monitor, atelevision, etc.), and may include one or more output device controllers5407, such as a video processor. There may also be one or more userinput devices 5408, such as a remote control, keyboard, mouse, touchscreen, microphone, etc. The computing device 5400 may also include oneor more network interfaces, such as a network interface 5409, which maybe a wired interface, a wireless interface, or a combination of the two.The network interface 5409 may provide an interface for the computingdevice 5400 to communicate with a network 5410 (e.g., a RAN, or anyother network). The network interface 5409 may include a modem (e.g., acable modem), and the external network 5410 may include communicationlinks, an external network, an in-home network, a provider's wireless,coaxial, fiber, or hybrid fiber/coaxial distribution system (e.g., aDOCSIS network), or any other desired network. Additionally, thecomputing device 5400 may include a location-detecting device, such as aglobal positioning system (GPS) microprocessor 5411, which may beconfigured to receive and process global positioning signals anddetermine, with possible assistance from an external server and antenna,a geographic position of the computing device 5400.

The example in FIG. 54 may be a hardware configuration, although thecomponents shown may be implemented as software as well. Modificationsmay be made to add, remove, combine, divide, etc. components of thecomputing device 5400 as desired. Additionally, the components may beimplemented using basic computing devices and components, and the samecomponents (e.g., processor 5401, ROM storage 5402, display 5406, etc.)may be used to implement any of the other computing devices andcomponents described herein. For example, the various componentsdescribed herein may be implemented using computing devices havingcomponents such as a processor executing computer-executableinstructions stored on a computer-readable medium, as shown in FIG. 54.Some or all of the entities described herein may be software based, andmay co-exist in a common physical platform (e.g., a requesting entitymay be a separate software process and program from a dependent entity,both of which may be executed as software on a common computing device).

One or more features of the disclosure may be implemented in acomputer-usable data and/or computer-executable instructions, such as inone or more program modules, executed by one or more computers or otherdevices. Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types when executed by a processor ina computer or other data processing device. The computer executableinstructions may be stored on one or more computer readable media suchas a hard disk, optical disk, removable storage media, solid statememory, RAM, etc. The functionality of the program modules may becombined or distributed as desired. The functionality may be implementedin whole or in part in firmware or hardware equivalents such asintegrated circuits, field programmable gate arrays (FPGA), and thelike. Particular data structures may be used to more effectivelyimplement one or more features of the disclosure, and such datastructures are contemplated within the scope of computer executableinstructions and computer-usable data described herein.

Many of the elements in examples may be implemented as modules. A modulemay be an isolatable element that performs a defined function and has adefined interface to other elements. The modules may be implemented inhardware, software in combination with hardware, firmware, wetware(i.e., hardware with a biological element) or a combination thereof, allof which may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.Additionally or alternatively, it may be possible to implement modulesusing physical hardware that incorporates discrete or programmableanalog, digital and/or quantum hardware. Examples of programmablehardware may comprise: computers, microcontrollers, microprocessors,application-specific integrated circuits (ASICs); field programmablegate arrays (FPGAs); and complex programmable logic devices (CPLDs).Computers, microcontrollers, and microprocessors may be programmed usinglanguages such as assembly, C, C++ or the like. FPGAs, ASICs, and CPLDsmay be programmed using hardware description languages (HDL), such asVHSIC hardware description language (VHDL) or Verilog, which mayconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The above-mentioned technologiesmay be used in combination to achieve the result of a functional module.

A non-transitory tangible computer readable media may compriseinstructions executable by one or more processors configured to causeoperations of multi-carrier communications described herein. An articleof manufacture may comprise a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a device (e.g., a wirelessdevice, wireless communicator, a wireless device, a base station, andthe like) to allow operation of multi-carrier communications describedherein. The device, or one or more devices such as in a system, mayinclude one or more processors, memory, interfaces, and/or the like.Other examples may comprise communication networks comprising devicessuch as base stations, wireless devices or user equipment (wirelessdevice), servers, switches, antennas, and/or the like. A network maycomprise any wireless technology, including but not limited to,cellular, wireless, WiFi, 4G, 5G, any generation of 3GPP or othercellular standard or recommendation, wireless local area networks,wireless personal area networks, wireless ad hoc networks, wirelessmetropolitan area networks, wireless wide area networks, global areanetworks, space networks, and any other network using wirelesscommunications. Any device (e.g., a wireless device, a base station, orany other device) or combination of devices may be used to perform anycombination of one or more of steps described herein, including, e.g.,any complementary step or steps of one or more of the above steps.

Although examples are described above, features and/or steps of thoseexamples may be combined, divided, omitted, rearranged, revised, and/oraugmented in any desired manner Various alterations, modifications, andimprovements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis description, though not expressly stated herein, and are intendedto be within the spirit and scope of the disclosure. Accordingly, theforegoing description is by way of example only, and is not limiting.

What is claimed is:
 1. A method comprising: receiving, by a wirelessdevice, at least one message comprising at least one configurationparameter indicating: a first random-access channel (RACH) resource fora first reference signal (RS) associated with a first beam, wherein thefirst RS is configured for beam failure detection; and a second RACHresource for a second RS associated with a second beam, wherein thesecond RS is configured for beam failure detection; and during a timeperiod in which the first beam and the second beam are configured asserving beams for the wireless device for downlink channel transmission:determining, based on a first measurement of the first RS not satisfyinga threshold, a beam failure of the first beam; and based on the beamfailure and based on a second measurement of the second RS satisfyingthe threshold, sending, via the second RACH resource for the second RS,a preamble.
 2. The method of claim 1, wherein the threshold comprises atleast one of: a minimum block error rate (BLER); or a minimum referencesignal received power (RSRP).
 3. The method of claim 1, wherein the atleast one configuration parameter indicates a third RACH resource for athird RS associated with a third beam, wherein the third RS isconfigured for beam failure detection.
 4. The method of claim 3, furthercomprising: determining, based on a third measurement of the third RSnot satisfying the threshold, a beam failure of the third beam.
 5. Themethod of claim 3, further comprising: determining that a thirdmeasurement of the third RS exceeds the threshold; and selecting, basedon the second measurement exceeding the third measurement, the second RSfor sending the preamble.
 6. The method of claim 3, further comprising:determining that a third measurement of the third RS exceeds thethreshold; and selecting, based on a random selection between the secondRS and the third RS, the second RS for sending the preamble.
 7. Themethod of claim 1, further comprising: determining a partial beamfailure associated with serving beams of a cell, wherein the partialbeam failure is based on: the first measurement of the first RS notsatisfying the threshold; and the second measurement of the second RSsatisfying the threshold.
 8. The method of claim 1, wherein the first RSis associated with a first transmission and reception point (TRP) andwherein the second RS is associated with a second TRP.
 9. The method ofclaim 1, further comprising: measuring, for beam failure detectionassociated with the first beam, a reference signal received power (RSRP)of the first RS; and measuring, for beam failure detection associatedwith the second beam, an RSRP of the second RS.
 10. The method of claim1, further comprising: after sending the preamble, determining that eachRS, of a plurality of RSs configured for beam failure detection, is notsatisfying the threshold; based on the determining that each RS, of theplurality of RSs configured for beam failure detection, is notsatisfying the threshold, determining a candidate beam RS; and sending,via a RACH resource for the candidate beam RS, a second preamble.
 11. Amethod comprising: receiving, by a wireless device, at least one messagecomprising at least one configuration parameter indicating: a firstresource for a first reference signal (RS), wherein the first RS isassociated with beam failure detection of a first beam; and a secondresource for a second RS, wherein the second RS is associated with beamfailure detection of a second beam; and during a time period in whichthe first beam and the second beam are configured as serving beams forthe wireless device for downlink channel transmission: determining,based on a first measurement of the first RS not satisfying a threshold,a beam failure of the first beam; and based on the beam failure andbased on a second measurement of the second RS satisfying the threshold,sending, via the second resource for the second RS, a beam failureindication associated with the first beam.
 12. The method of claim 11,wherein the threshold comprises at least one of: a minimum block errorrate (BLER); or a minimum reference signal received power (RSRP). 13.The method of claim 11, wherein the beam failure indication comprises atleast one of: a preamble; or a beam failure recovery request.
 14. Themethod of claim 11, further comprising: determining, based on a thirdmeasurement of the second RS not satisfying the threshold, a beamfailure of the second beam; selecting, based on the beam failure of thesecond beam and based on a fourth measurement of a third RS satisfyingthe threshold, the third RS for sending a second beam failureindication; and sending, via a third resource for the third RS, thesecond beam failure indication, wherein the third RS is associated withbeam failure detection of a third beam.
 15. The method of claim 11,further comprising: determining a partial beam failure associated withserving beams of a cell, wherein the partial beam failure is determinedbased on: the first measurement of the first RS not satisfying thethreshold; and the second measurement of the second RS satisfying thethreshold.
 16. The method of claim 11, wherein the first RS isassociated with a first transmission and reception point (TRP) andwherein the second RS is associated with a second TRP.
 17. The method ofclaim 11, further comprising: receiving a plurality of reference signals(RSs) associated with beam failure detection of a cell, wherein theplurality of RSs comprise the first RS and the second RS; determiningthat at least one measurement of a first subset of the plurality of RSsdoes not satisfy the threshold and that at least one measurement of asecond subset of the plurality of RSs satisfies the threshold; andselecting, from among the second subset, the second RS for sending thebeam failure indication.
 18. The method of claim 11, further comprising:receiving a plurality of reference signals (RSs) associated with beamfailure detection of a cell, wherein the plurality of RSs comprise thefirst RS and the second RS; and after sending the beam failureindication, determining, based on measurements of the plurality of RSsnot satisfying the threshold, at least one measurement of at least onecandidate beam RS for beam failure recovery of the cell.
 19. The methodof claim 11, wherein the beam failure indication comprises at least oneof: a preamble via a random access channel; a partial beam failurerecovery request via a physical uplink control channel; or a partialbeam failure recovery request via at least one serving beam.
 20. Themethod of claim 11, wherein the second resource comprises a physicaluplink control channel (PUCCH) resource for beam failure recoveryassociated with the first RS.
 21. The method of claim 9, wherein thefirst resource comprises a physical uplink control channel (PUCCH)resource for beam failure recovery associated with the second RS.
 22. Amethod comprising: receiving, by a wireless device, at least oneconfiguration parameter indicating a plurality of reference signals(RSs) for beam failure detection; and during a time period in which theplurality of RSs are configured as beam failure detection RSs forserving beams of the wireless device: determining, based on a firstmeasurement of a first reference signal (RS) of the plurality of RSs notsatisfying a threshold and based on a second measurement of a second RSof the plurality of RSs satisfying the threshold, a beam failureassociated with a subset of the plurality of RSs; based on the beamfailure and based on the second measurement satisfying the threshold,selecting a beam associated with the second RS for sending a beamfailure indication associated with the beam failure; and sending, viathe beam associated with the second RS, the beam failure indication. 23.The method of claim 22, wherein the threshold comprises at least one of:a minimum block error rate (BLER); or a minimum reference signalreceived power (RSRP).
 24. The method of claim 22, wherein the first RSis associated with a first transmission and reception point (TRP) andwherein the second RS is associated with a second TRP.
 25. The method ofclaim 22, further comprising: determining that at least one measurementof the subset of the plurality of RSs does not satisfy the threshold andthat at least one measurement of a second subset of the plurality of RSssatisfies the threshold, wherein the subset of the plurality of RSscomprises the first RS, wherein selecting the second RS comprisesselecting, from among the second subset, the second RS for sending thebeam failure indication.
 26. The method of claim 22, further comprising:after sending the beam failure indication, determining, based onmeasurements of the plurality of RSs not satisfying the threshold, atleast one measurement of at least one candidate beam RS for beam failurerecovery.
 27. The method of claim 22, wherein the beam failureindication comprises at least one of: a preamble via a random accesschannel; a partial beam failure recovery request via a physical uplinkcontrol channel; or a partial beam failure recovery request via at leastone serving beam.
 28. A wireless device comprising: one or moreprocessors; and memory storing instructions that, when executed by theone or more processors, cause the wireless device to: receive at leastone message comprising at least one configuration parameter indicating:a first random-access channel (RACH) resource for a first referencesignal (RS) associated with a first beam, wherein the first RS isconfigured for beam failure detection; and a second RACH resource for asecond RS associated with a second beam, wherein the second RS isconfigured for beam failure detection; and during a time period in whichthe first beam and the second beam are configured as serving beams forthe wireless device for downlink channel transmission: determine, basedon a first measurement of the first RS not satisfying a threshold, abeam failure of the first beam; and based on the beam failure and basedon a second measurement of the second RS satisfying the threshold, send,via the second RACH resource for the second RS, a preamble.
 29. Thewireless device of claim 28, wherein the threshold comprises at leastone of: a minimum block error rate (BLER); or a minimum reference signalreceived power (RSRP).
 30. The wireless device of claim 28, wherein theat least one configuration parameter indicates a third RACH resource fora third RS associated with a third beam, wherein the third RS isconfigured for beam failure detection.
 31. The wireless device of claim30, wherein the instructions, when executed by the one or moreprocessors, cause the wireless device to: determine, based on a thirdmeasurement of the third RS not satisfying the threshold, a beam failureof the third beam.
 32. The wireless device of claim 30, wherein theinstructions, when executed by the one or more processors, cause thewireless device to: determine that a third measurement of the third RSexceeds the threshold; and select, based on the second measurementexceeding the third measurement, the second RS for sending the preamble.33. The wireless device of claim 30, wherein the instructions, whenexecuted by the one or more processors, cause the wireless device to:determine that a third measurement of the third RS exceeds thethreshold; and select, based on a random selection between the second RSand the third RS, the second RS for sending the preamble.
 34. Thewireless device of claim 28, wherein the instructions, when executed bythe one or more processors, cause the wireless device to: determine apartial beam failure associated with serving beams of a cell, whereinthe partial beam failure is based on: the first measurement of the firstRS not satisfying the threshold; and the second measurement of thesecond RS satisfying the threshold.
 35. The wireless device of claim 28,wherein the first RS is associated with a first transmission andreception point (TRP) and wherein the second RS is associated with asecond TRP.
 36. The wireless device of claim 28, wherein theinstructions, when executed by the one or more processors, cause thewireless device to: measure, for beam failure detection associated withthe first beam, a reference signal received power (RSRP) of the firstRS; and measure, for beam failure detection associated with the secondbeam, an RSRP of the second RS.
 37. The wireless device of claim 28,wherein the instructions, when executed by the one or more processors,cause the wireless device to: after sending the preamble, determine thateach RS, of a plurality of RSs configured for beam failure detection, isnot satisfying the threshold; based on determining that each RS, of theplurality of RSs configured for beam failure detection, is notsatisfying the threshold, determine a candidate beam RS; and send, via aRACH resource for the candidate beam RS, a second preamble.
 38. Awireless device comprising: one or more processors; and memory storinginstructions that, when executed by the one or more processors, causethe wireless device to: receive at least one message comprising at leastone configuration parameter indicating: a first resource for a firstreference signal (RS), wherein the first RS is associated with beamfailure detection of a first beam; and a second resource for a secondRS, wherein the second RS is associated with beam failure detection of asecond beam; and during a time period in which the first beam and thesecond beam are configured as serving beams for the wireless device fordownlink channel transmission: determine, based on a first measurementof the first RS not satisfying a threshold, a beam failure of the firstbeam; and based on the beam failure and based on a second measurement ofthe second RS satisfying the threshold, send, via the second resourcefor the second RS, a beam failure indication associated with the firstbeam.
 39. The wireless device of claim 38, wherein the thresholdcomprises at least one of: a minimum block error rate (BLER); or aminimum reference signal received power (RSRP).
 40. The wireless deviceof claim 38, wherein the beam failure indication comprises at least oneof: a preamble; or a beam failure recovery request.
 41. The wirelessdevice of claim 38, wherein the instructions, when executed by the oneor more processors, cause the wireless device to: determine, based on athird measurement of the second RS not satisfying the threshold, a beamfailure of the second beam; select, based on the beam failure of thesecond beam and based on a fourth measurement of a third RS satisfyingthe threshold, the third RS for sending a second beam failureindication; and send, via a third resource for the third RS, the secondbeam failure indication, wherein the third RS is associated with beamfailure detection of a third beam.
 42. The wireless device of claim 38,wherein the instructions, when executed by the one or more processors,cause the wireless device to: determine a partial beam failureassociated with serving beams of a cell, wherein the partial beamfailure is determined based on: the first measurement of the first RSnot satisfying the threshold; and the second measurement of the secondRS satisfying the threshold.
 43. The wireless device of claim 38,wherein the first RS is associated with a first transmission andreception point (TRP) and wherein the second RS is associated with asecond TRP.
 44. The wireless device of claim 38, wherein theinstructions, when executed by the one or more processors, cause thewireless device to: receive a plurality of reference signals (RSs)associated with beam failure detection of a cell, wherein the pluralityof RSs comprise the first RS and the second RS; determine that at leastone measurement of a first subset of the plurality of RSs does notsatisfy the threshold and that at least one measurement of a secondsubset of the plurality of RSs satisfies the threshold; and select, fromamong the second subset, the second RS for sending the beam failureindication.
 45. The wireless device of claim 38, wherein theinstructions, when executed by the one or more processors, cause thewireless device to: receive a plurality of reference signals (RSs)associated with beam failure detection of a cell, wherein the pluralityof RSs comprise the first RS and the second RS; and after sending thebeam failure indication, determine, based on measurements of theplurality of RSs not satisfying the threshold, at least one measurementof at least one candidate beam RS for beam failure recovery of the cell.46. The wireless device of claim 38, wherein the beam failure indicationcomprises at least one of: a preamble via a random access channel; apartial beam failure recovery request via a physical uplink controlchannel; or a partial beam failure recovery request via at least oneserving beam.
 47. The wireless device of claim 38, wherein the secondresource comprises a physical uplink control channel (PUCCH) resourcefor beam failure recovery associated with the first RS.
 48. The wirelessdevice of claim 38, wherein the first resource comprises a physicaluplink control channel (PUCCH) resource for beam failure recoveryassociated with the second RS.
 49. A wireless device comprising: one ormore processors; and memory storing instructions that, when executed bythe one or more processors, cause the wireless device to: receive atleast one configuration parameter indicating a plurality of referencesignals (RSs) for beam failure detection; and during a time period inwhich the plurality of RSs are configured as beam failure detection RSsfor serving beams of the wireless device: determine, based on a firstmeasurement of a first reference signal (RS) of the plurality of RSs notsatisfying a threshold and based on a second measurement of a second RSof the plurality of RSs satisfying the threshold, a beam failureassociated with a subset of the plurality of RSs; based on the beamfailure and based on the second measurement satisfying the threshold,select a beam associated with the second RS for sending a beam failureindication associated with the beam failure; and send, via the beamassociated with the second RS, the beam failure indication.
 50. Thewireless device of claim 49, wherein the threshold comprises at leastone of: a minimum block error rate (BLER); or a minimum reference signalreceived power (RSRP).
 51. The wireless device of claim 49, wherein thefirst RS is associated with a first transmission and reception point(TRP) and wherein the second RS is associated with a second TRP.
 52. Thewireless device of claim 49, wherein the instructions, when executed bythe one or more processors, cause the wireless device to: determine thatat least one measurement of the subset of the plurality of RSs does notsatisfy the threshold and that at least one measurement of a secondsubset of the plurality of RSs satisfies the threshold, wherein thesubset of the plurality of RSs comprises the first RS; and select, fromamong the second subset, the second RS for sending the beam failureindication.
 53. The wireless device of claim 49, wherein theinstructions, when executed by the one or more processors, cause thewireless device to: after sending the beam failure indication,determine, based on measurements of the plurality of RSs not satisfyingthe threshold, at least one measurement of at least one candidate beamRS for beam failure recovery.
 54. The wireless device of claim 49,wherein the beam failure indication comprises at least one of: apreamble via a random access channel; a partial beam failure recoveryrequest via a physical uplink control channel; or a partial beam failurerecovery request via at least one serving beam.